diff --git a/src/Makefile.am b/src/Makefile.am
index 83690a923637..c266dc4a7055 100644
--- a/src/Makefile.am
+++ b/src/Makefile.am
@@ -260,13 +260,21 @@ BITCOIN_CORE_H = \
   ui_interface.h \
   undo.h \
   unordered_lru_cache.h \
-  util.h \
-  utilasmap.h \
-  utilmemory.h \
-  utilmoneystr.h \
-  utilstring.h \
-  utiltime.h \
-  utilthreadnames.h \
+  util/bytevectorhash.h \
+  util/error.h \
+  util/fees.h \
+  util/system.h \
+  util/asmap.h \
+  util/macros.h \
+  util/memory.h \
+  util/moneystr.h \
+  util/serfloat.h \
+  util/string.h \
+  util/time.h \
+  util/threadnames.h \
+  util/vector.h \
+  util/url.h \
+  util/validation.h \
   validation.h \
   validationinterface.h \
   versionbits.h \
@@ -444,7 +452,9 @@ crypto_libdash_crypto_base_a_SOURCES = \
   crypto/sha3.cpp \
   crypto/sha3.h \
   crypto/sha512.cpp \
-  crypto/sha512.h
+  crypto/sha512.h \
+  crypto/siphash.cpp \
+  crypto/siphash.h
 
 if USE_ASM
 crypto_libdash_crypto_base_a_SOURCES += crypto/sha256_sse4.cpp
@@ -529,8 +539,8 @@ libdash_consensus_a_SOURCES = \
   tinyformat.h \
   uint256.cpp \
   uint256.h \
-  utilstrencodings.cpp \
-  utilstrencodings.h \
+  util/strencodings.cpp \
+  util/strencodings.h \
   version.h
 
 # common: shared between dashd, and dash-qt and non-server tools
@@ -588,13 +598,19 @@ libdash_util_a_SOURCES = \
   support/cleanse.cpp \
   sync.cpp \
   threadinterrupt.cpp \
-  util.cpp \
-  utilasmap.cpp \
-  utilmoneystr.cpp \
-  utilstrencodings.cpp \
-  utiltime.cpp \
-  utilstring.cpp \
-  utilthreadnames.cpp \
+  util/bytevectorhash.cpp \
+  util/error.cpp \
+  util/fees.cpp \
+  util/system.cpp \
+  util/asmap.cpp \
+  util/moneystr.cpp \
+  util/strencodings.cpp \
+  util/time.cpp \
+  util/serfloat.cpp \
+  util/string.cpp \
+  util/threadnames.cpp \
+  util/url.cpp \
+  util/validation.cpp \
   $(BITCOIN_CORE_H)
 
 if GLIBC_BACK_COMPAT
diff --git a/src/addrdb.cpp b/src/addrdb.cpp
index c7183b226c7d..4023cf7d0d0f 100644
--- a/src/addrdb.cpp
+++ b/src/addrdb.cpp
@@ -12,7 +12,7 @@
 #include <random.h>
 #include <streams.h>
 #include <tinyformat.h>
-#include <util.h>
+#include <util/system.h>
 
 namespace {
 
diff --git a/src/addrman.h b/src/addrman.h
index 3c725a0172f3..26c03c4c7ae1 100644
--- a/src/addrman.h
+++ b/src/addrman.h
@@ -13,7 +13,7 @@
 #include <sync.h>
 #include <timedata.h>
 #include <tinyformat.h>
-#include <util.h>
+#include <util/system.h>
 
 #include <fs.h>
 #include <hash.h>
diff --git a/src/arith_uint256.cpp b/src/arith_uint256.cpp
index ea08dbf55d53..cdde91c568ee 100644
--- a/src/arith_uint256.cpp
+++ b/src/arith_uint256.cpp
@@ -6,7 +6,7 @@
 #include <arith_uint256.h>
 
 #include <uint256.h>
-#include <utilstrencodings.h>
+#include <util/strencodings.h>
 #include <crypto/common.h>
 
 #include <stdio.h>
diff --git a/src/attributes.h b/src/attributes.h
index 9d5c1d44a04c..995c24e13f04 100644
--- a/src/attributes.h
+++ b/src/attributes.h
@@ -6,19 +6,6 @@
 #ifndef BITCOIN_ATTRIBUTES_H
 #define BITCOIN_ATTRIBUTES_H
 
-#if defined(__has_cpp_attribute)
-#  if __has_cpp_attribute(nodiscard)
-#    define NODISCARD [[nodiscard]]
-#  endif
-#endif
-#ifndef NODISCARD
-#  if defined(_MSC_VER) && _MSC_VER >= 1700
-#    define NODISCARD _Check_return_
-#  else
-#    define NODISCARD __attribute__((warn_unused_result))
-#  endif
-#endif
-
 #if defined(__clang__)
 #  if __has_attribute(lifetimebound)
 #    define LIFETIMEBOUND [[clang::lifetimebound]]
diff --git a/src/base58.cpp b/src/base58.cpp
index f2f0f1373ea2..306547ce1e2e 100644
--- a/src/base58.cpp
+++ b/src/base58.cpp
@@ -6,8 +6,8 @@
 
 #include <hash.h>
 #include <uint256.h>
-#include <utilstrencodings.h>
-#include <utilstring.h>
+#include <util/strencodings.h>
+#include <util/string.h>
 
 #include <assert.h>
 #include <stdint.h>
diff --git a/src/base58.h b/src/base58.h
index 230e4392a3c8..038e3288cd3f 100644
--- a/src/base58.h
+++ b/src/base58.h
@@ -35,13 +35,13 @@ std::string EncodeBase58(const std::vector<unsigned char>& vch);
  * return true if decoding is successful.
  * psz cannot be nullptr.
  */
-NODISCARD bool DecodeBase58(const char* psz, std::vector<unsigned char>& vchRet);
+[[nodiscard]] bool DecodeBase58(const char* psz, std::vector<unsigned char>& vchRet);
 
 /**
  * Decode a base58-encoded string (str) into a byte vector (vchRet).
  * return true if decoding is successful.
  */
-NODISCARD bool DecodeBase58(const std::string& str, std::vector<unsigned char>& vchRet);
+[[nodiscard]] bool DecodeBase58(const std::string& str, std::vector<unsigned char>& vchRet);
 
 /**
  * Encode a byte vector into a base58-encoded string, including checksum
@@ -52,12 +52,12 @@ std::string EncodeBase58Check(const std::vector<unsigned char>& vchIn);
  * Decode a base58-encoded string (psz) that includes a checksum into a byte
  * vector (vchRet), return true if decoding is successful
  */
-NODISCARD bool DecodeBase58Check(const char* psz, std::vector<unsigned char>& vchRet);
+[[nodiscard]] bool DecodeBase58Check(const char* psz, std::vector<unsigned char>& vchRet);
 
 /**
  * Decode a base58-encoded string (str) that includes a checksum into a byte
  * vector (vchRet), return true if decoding is successful
  */
-NODISCARD bool DecodeBase58Check(const std::string& str, std::vector<unsigned char>& vchRet);
+[[nodiscard]] bool DecodeBase58Check(const std::string& str, std::vector<unsigned char>& vchRet);
 
 #endif // BITCOIN_BASE58_H
diff --git a/src/batchedlogger.cpp b/src/batchedlogger.cpp
index 009dc405dc65..55aaa7fec6d2 100644
--- a/src/batchedlogger.cpp
+++ b/src/batchedlogger.cpp
@@ -3,7 +3,7 @@
 // file COPYING or http://www.opensource.org/licenses/mit-license.php.
 
 #include <batchedlogger.h>
-#include <util.h>
+#include <util/system.h>
 
 CBatchedLogger::CBatchedLogger(BCLog::LogFlags _category, const std::string& _header) :
     accept(LogAcceptCategory(_category)), header(_header)
diff --git a/src/bech32.cpp b/src/bech32.cpp
index c55f22b9b75f..d1ad9c0cb19c 100644
--- a/src/bech32.cpp
+++ b/src/bech32.cpp
@@ -3,6 +3,7 @@
 // file COPYING or http://www.opensource.org/licenses/mit-license.php.
 
 #include <bech32.h>
+#include <util/vector.h>
 
 namespace
 {
@@ -24,13 +25,6 @@ const int8_t CHARSET_REV[128] = {
      1,  0,  3, 16, 11, 28, 12, 14,  6,  4,  2, -1, -1, -1, -1, -1
 };
 
-/** Concatenate two byte arrays. */
-data Cat(data x, const data& y)
-{
-    x.insert(x.end(), y.begin(), y.end());
-    return x;
-}
-
 /** This function will compute what 6 5-bit values to XOR into the last 6 input values, in order to
  *  make the checksum 0. These 6 values are packed together in a single 30-bit integer. The higher
  *  bits correspond to earlier values. */
diff --git a/src/bench/bench_dash.cpp b/src/bench/bench_dash.cpp
index fece0a9d263a..fcbc5f50ac10 100644
--- a/src/bench/bench_dash.cpp
+++ b/src/bench/bench_dash.cpp
@@ -8,7 +8,7 @@
 #include <key.h>
 #include <stacktraces.h>
 #include <validation.h>
-#include <util.h>
+#include <util/system.h>
 #include <random.h>
 
 #include <boost/lexical_cast.hpp>
diff --git a/src/bench/bls.cpp b/src/bench/bls.cpp
index 28f7cbef9d7a..8e1e92c2c004 100644
--- a/src/bench/bls.cpp
+++ b/src/bench/bls.cpp
@@ -5,7 +5,7 @@
 #include <bench/bench.h>
 #include <random.h>
 #include <bls/bls_worker.h>
-#include <utiltime.h>
+#include <util/time.h>
 
 #include <iostream>
 
diff --git a/src/bench/checkqueue.cpp b/src/bench/checkqueue.cpp
index b0a92ab08879..1bb81809d91f 100644
--- a/src/bench/checkqueue.cpp
+++ b/src/bench/checkqueue.cpp
@@ -3,7 +3,7 @@
 // file COPYING or http://www.opensource.org/licenses/mit-license.php.
 
 #include <bench/bench.h>
-#include <util.h>
+#include <util/system.h>
 #include <validation.h>
 #include <checkqueue.h>
 #include <prevector.h>
diff --git a/src/bench/crypto_hash.cpp b/src/bench/crypto_hash.cpp
index 65377ac0cd34..783df8368a0b 100644
--- a/src/bench/crypto_hash.cpp
+++ b/src/bench/crypto_hash.cpp
@@ -10,12 +10,13 @@
 #include <hash.h>
 #include <random.h>
 #include <uint256.h>
-#include <utiltime.h>
+#include <util/time.h>
 #include <crypto/ripemd160.h>
 #include <crypto/sha1.h>
 #include <crypto/sha256.h>
 #include <crypto/sha3.h>
 #include <crypto/sha512.h>
+#include <crypto/siphash.h>
 
 /* Number of bytes to hash per iteration */
 static const uint64_t BUFFER_SIZE = 1000*1000;
diff --git a/src/bench/examples.cpp b/src/bench/examples.cpp
index 718dd6064a10..f54664c2a09f 100644
--- a/src/bench/examples.cpp
+++ b/src/bench/examples.cpp
@@ -4,7 +4,7 @@
 
 #include <bench/bench.h>
 #include <validation.h>
-#include <utiltime.h>
+#include <util/time.h>
 
 // Sanity test: this should loop ten times, and
 // min/max/average should be close to 100ms.
diff --git a/src/bench/string_cast.cpp b/src/bench/string_cast.cpp
index da285c6e58b2..3cdb161d5534 100644
--- a/src/bench/string_cast.cpp
+++ b/src/bench/string_cast.cpp
@@ -4,7 +4,7 @@
 
 #include <bench/bench.h>
 #include <tinyformat.h>
-#include <utilstrencodings.h>
+#include <util/strencodings.h>
 
 #include <boost/lexical_cast.hpp>
 #include <string>
diff --git a/src/bench/util_time.cpp b/src/bench/util_time.cpp
index 94cef29ac975..72d97354aa55 100644
--- a/src/bench/util_time.cpp
+++ b/src/bench/util_time.cpp
@@ -4,7 +4,7 @@
 
 #include <bench/bench.h>
 
-#include <utiltime.h>
+#include <util/time.h>
 
 static void BenchTimeDeprecated(benchmark::State& state)
 {
diff --git a/src/blockencodings.cpp b/src/blockencodings.cpp
index daa3aa0b553b..e6cc07e81b5b 100644
--- a/src/blockencodings.cpp
+++ b/src/blockencodings.cpp
@@ -6,12 +6,13 @@
 #include <consensus/consensus.h>
 #include <consensus/validation.h>
 #include <chainparams.h>
-#include <hash.h>
+#include <crypto/sha256.h>
+#include <crypto/siphash.h>
 #include <random.h>
 #include <streams.h>
 #include <txmempool.h>
 #include <validation.h>
-#include <util.h>
+#include <util/system.h>
 
 #include <unordered_map>
 
diff --git a/src/blockfilter.cpp b/src/blockfilter.cpp
index 271104fc62e3..366958102367 100644
--- a/src/blockfilter.cpp
+++ b/src/blockfilter.cpp
@@ -3,6 +3,7 @@
 // file COPYING or http://www.opensource.org/licenses/mit-license.php.
 
 #include <blockfilter.h>
+#include <crypto/siphash.h>
 #include <hash.h>
 #include <primitives/transaction.h>
 #include <script/script.h>
diff --git a/src/blockfilter.h b/src/blockfilter.h
index 2ad044ce2428..667530738abe 100644
--- a/src/blockfilter.h
+++ b/src/blockfilter.h
@@ -5,14 +5,15 @@
 #ifndef BITCOIN_BLOCKFILTER_H
 #define BITCOIN_BLOCKFILTER_H
 
-#include <set>
 #include <stdint.h>
+#include <unordered_set>
 #include <vector>
 
 #include <primitives/block.h>
 #include <serialize.h>
 #include <uint256.h>
 #include <undo.h>
+#include <util/bytevectorhash.h>
 
 /**
  * This implements a Golomb-coded set as defined in BIP 158. It is a
@@ -22,7 +23,7 @@ class GCSFilter
 {
 public:
     typedef std::vector<unsigned char> Element;
-    typedef std::set<Element> ElementSet;
+    typedef std::unordered_set<Element, ByteVectorHash> ElementSet;
 
 private:
     uint64_t m_siphash_k0;
diff --git a/src/bls/bls.h b/src/bls/bls.h
index c21e677f762d..d1bace3218df 100644
--- a/src/bls/bls.h
+++ b/src/bls/bls.h
@@ -8,7 +8,7 @@
 #include <hash.h>
 #include <serialize.h>
 #include <uint256.h>
-#include <utilstrencodings.h>
+#include <util/strencodings.h>
 
 // bls-dash uses relic, which may define DEBUG and ERROR, which leads to many warnings in some build setups
 #undef ERROR
diff --git a/src/bls/bls_worker.cpp b/src/bls/bls_worker.cpp
index 7707bd71e719..5cf8aab1733b 100644
--- a/src/bls/bls_worker.cpp
+++ b/src/bls/bls_worker.cpp
@@ -6,7 +6,7 @@
 #include <hash.h>
 #include <serialize.h>
 
-#include <util.h>
+#include <util/system.h>
 
 #include <memory>
 #include <utility>
diff --git a/src/chainparams.cpp b/src/chainparams.cpp
index 62ebee43aaee..98395dfec67a 100644
--- a/src/chainparams.cpp
+++ b/src/chainparams.cpp
@@ -8,8 +8,8 @@
 #include <consensus/merkle.h>
 
 #include <tinyformat.h>
-#include <util.h>
-#include <utilstrencodings.h>
+#include <util/system.h>
+#include <util/strencodings.h>
 
 #include <arith_uint256.h>
 
diff --git a/src/chainparamsbase.cpp b/src/chainparamsbase.cpp
index 42fec52de0da..fa504c4b6a84 100644
--- a/src/chainparamsbase.cpp
+++ b/src/chainparamsbase.cpp
@@ -6,8 +6,8 @@
 #include <chainparamsbase.h>
 
 #include <tinyformat.h>
-#include <util.h>
-#include <utilmemory.h>
+#include <util/system.h>
+#include <util/memory.h>
 
 #include <assert.h>
 
diff --git a/src/checkqueue.h b/src/checkqueue.h
index 1254852e6d87..9112860c4e18 100644
--- a/src/checkqueue.h
+++ b/src/checkqueue.h
@@ -7,7 +7,7 @@
 
 #include <sync.h>
 #include <tinyformat.h>
-#include <utilthreadnames.h>
+#include <util/threadnames.h>
 
 #include <algorithm>
 #include <vector>
diff --git a/src/coinjoin/coinjoin-client-options.cpp b/src/coinjoin/coinjoin-client-options.cpp
index 22e74e93fc3f..738c54ba002c 100644
--- a/src/coinjoin/coinjoin-client-options.cpp
+++ b/src/coinjoin/coinjoin-client-options.cpp
@@ -4,7 +4,7 @@
 
 #include <coinjoin/coinjoin-client-options.h>
 
-#include <util.h>
+#include <util/system.h>
 #include <univalue.h>
 
 #include <cassert>
diff --git a/src/coinjoin/coinjoin-client.cpp b/src/coinjoin/coinjoin-client.cpp
index 77b9cf2115fd..e03fdd349d09 100644
--- a/src/coinjoin/coinjoin-client.cpp
+++ b/src/coinjoin/coinjoin-client.cpp
@@ -15,8 +15,8 @@
 #include <net_processing.h>
 #include <script/sign.h>
 #include <txmempool.h>
-#include <util.h>
-#include <utilmoneystr.h>
+#include <util/system.h>
+#include <util/moneystr.h>
 #include <validation.h>
 #include <version.h>
 #include <wallet/coincontrol.h>
diff --git a/src/coinjoin/coinjoin-server.cpp b/src/coinjoin/coinjoin-server.cpp
index f63553c4ae50..b24698550f4e 100644
--- a/src/coinjoin/coinjoin-server.cpp
+++ b/src/coinjoin/coinjoin-server.cpp
@@ -15,8 +15,8 @@
 #include <netmessagemaker.h>
 #include <script/interpreter.h>
 #include <txmempool.h>
-#include <util.h>
-#include <utilmoneystr.h>
+#include <util/system.h>
+#include <util/moneystr.h>
 #include <validation.h>
 #include <version.h>
 
diff --git a/src/coinjoin/coinjoin.cpp b/src/coinjoin/coinjoin.cpp
index bcdfcac0e1f2..6c4f06f201d5 100644
--- a/src/coinjoin/coinjoin.cpp
+++ b/src/coinjoin/coinjoin.cpp
@@ -11,8 +11,8 @@
 #include <netmessagemaker.h>
 #include <script/sign.h>
 #include <txmempool.h>
-#include <util.h>
-#include <utilmoneystr.h>
+#include <util/system.h>
+#include <util/moneystr.h>
 #include <validation.h>
 #include <bls/bls.h>
 #include <masternode/activemasternode.h>
diff --git a/src/coins.cpp b/src/coins.cpp
index 1b52d687624b..d7670cc1c6e4 100644
--- a/src/coins.cpp
+++ b/src/coins.cpp
@@ -6,6 +6,7 @@
 
 #include <consensus/consensus.h>
 #include <random.h>
+#include <version.h>
 
 bool CCoinsView::GetCoin(const COutPoint &outpoint, Coin &coin) const { return false; }
 uint256 CCoinsView::GetBestBlock() const { return uint256(); }
diff --git a/src/coins.h b/src/coins.h
index 2034477c7721..208d04763371 100644
--- a/src/coins.h
+++ b/src/coins.h
@@ -9,7 +9,7 @@
 #include <primitives/transaction.h>
 #include <compressor.h>
 #include <core_memusage.h>
-#include <hash.h>
+#include <crypto/siphash.h>
 #include <memusage.h>
 #include <serialize.h>
 #include <uint256.h>
diff --git a/src/consensus/merkle.cpp b/src/consensus/merkle.cpp
index 47b4c50cdaf1..307bd62c1d1b 100644
--- a/src/consensus/merkle.cpp
+++ b/src/consensus/merkle.cpp
@@ -4,7 +4,7 @@
 
 #include <consensus/merkle.h>
 #include <hash.h>
-#include <utilstrencodings.h>
+#include <util/strencodings.h>
 
 /*     WARNING! If you're reading this because you're learning about crypto
        and/or designing a new system that will use merkle trees, keep in mind
diff --git a/src/consensus/tx_verify.cpp b/src/consensus/tx_verify.cpp
index 87d46aa604f7..6aeef5e283e1 100644
--- a/src/consensus/tx_verify.cpp
+++ b/src/consensus/tx_verify.cpp
@@ -12,7 +12,8 @@
 // TODO remove the following dependencies
 #include <chain.h>
 #include <coins.h>
-#include <utilmoneystr.h>
+#include <util/moneystr.h>
+#include <version.h>
 
 bool IsFinalTx(const CTransaction &tx, int nBlockHeight, int64_t nBlockTime)
 {
diff --git a/src/core_io.h b/src/core_io.h
index 9d3f5145d056..7921c442fafa 100644
--- a/src/core_io.h
+++ b/src/core_io.h
@@ -23,8 +23,8 @@ struct CSpentIndexTxInfo;
 // core_read.cpp
 CScript ParseScript(const std::string& s);
 std::string ScriptToAsmStr(const CScript& script, const bool fAttemptSighashDecode = false);
-NODISCARD bool DecodeHexTx(CMutableTransaction& tx, const std::string& strHexTx);
-NODISCARD bool DecodeHexBlk(CBlock&, const std::string& strHexBlk);
+[[nodiscard]] bool DecodeHexTx(CMutableTransaction& tx, const std::string& strHexTx);
+[[nodiscard]] bool DecodeHexBlk(CBlock&, const std::string& strHexBlk);
 uint256 ParseHashStr(const std::string&, const std::string& strName);
 std::vector<unsigned char> ParseHexUV(const UniValue& v, const std::string& strName);
 
diff --git a/src/core_read.cpp b/src/core_read.cpp
index 3b5e4e70694e..8756c2f3bf19 100644
--- a/src/core_read.cpp
+++ b/src/core_read.cpp
@@ -10,8 +10,8 @@
 #include <serialize.h>
 #include <streams.h>
 #include <univalue.h>
-#include <util.h>
-#include <utilstrencodings.h>
+#include <util/system.h>
+#include <util/strencodings.h>
 #include <version.h>
 
 #include <boost/algorithm/string/classification.hpp>
diff --git a/src/core_write.cpp b/src/core_write.cpp
index 4481d41da2a8..4b438780bc99 100644
--- a/src/core_write.cpp
+++ b/src/core_write.cpp
@@ -13,9 +13,9 @@
 #include <serialize.h>
 #include <streams.h>
 #include <univalue.h>
-#include <util.h>
-#include <utilmoneystr.h>
-#include <utilstrencodings.h>
+#include <util/system.h>
+#include <util/moneystr.h>
+#include <util/strencodings.h>
 
 #include <spentindex.h>
 
diff --git a/src/crypto/siphash.cpp b/src/crypto/siphash.cpp
new file mode 100644
index 000000000000..e81957111ad2
--- /dev/null
+++ b/src/crypto/siphash.cpp
@@ -0,0 +1,173 @@
+// Copyright (c) 2016-2018 The Bitcoin Core developers
+// Distributed under the MIT software license, see the accompanying
+// file COPYING or http://www.opensource.org/licenses/mit-license.php.
+
+#include <crypto/siphash.h>
+
+#define ROTL(x, b) (uint64_t)(((x) << (b)) | ((x) >> (64 - (b))))
+
+#define SIPROUND do { \
+    v0 += v1; v1 = ROTL(v1, 13); v1 ^= v0; \
+    v0 = ROTL(v0, 32); \
+    v2 += v3; v3 = ROTL(v3, 16); v3 ^= v2; \
+    v0 += v3; v3 = ROTL(v3, 21); v3 ^= v0; \
+    v2 += v1; v1 = ROTL(v1, 17); v1 ^= v2; \
+    v2 = ROTL(v2, 32); \
+} while (0)
+
+CSipHasher::CSipHasher(uint64_t k0, uint64_t k1)
+{
+    v[0] = 0x736f6d6570736575ULL ^ k0;
+    v[1] = 0x646f72616e646f6dULL ^ k1;
+    v[2] = 0x6c7967656e657261ULL ^ k0;
+    v[3] = 0x7465646279746573ULL ^ k1;
+    count = 0;
+    tmp = 0;
+}
+
+CSipHasher& CSipHasher::Write(uint64_t data)
+{
+    uint64_t v0 = v[0], v1 = v[1], v2 = v[2], v3 = v[3];
+
+    assert(count % 8 == 0);
+
+    v3 ^= data;
+    SIPROUND;
+    SIPROUND;
+    v0 ^= data;
+
+    v[0] = v0;
+    v[1] = v1;
+    v[2] = v2;
+    v[3] = v3;
+
+    count += 8;
+    return *this;
+}
+
+CSipHasher& CSipHasher::Write(const unsigned char* data, size_t size)
+{
+    uint64_t v0 = v[0], v1 = v[1], v2 = v[2], v3 = v[3];
+    uint64_t t = tmp;
+    int c = count;
+
+    while (size--) {
+        t |= ((uint64_t)(*(data++))) << (8 * (c % 8));
+        c++;
+        if ((c & 7) == 0) {
+            v3 ^= t;
+            SIPROUND;
+            SIPROUND;
+            v0 ^= t;
+            t = 0;
+        }
+    }
+
+    v[0] = v0;
+    v[1] = v1;
+    v[2] = v2;
+    v[3] = v3;
+    count = c;
+    tmp = t;
+
+    return *this;
+}
+
+uint64_t CSipHasher::Finalize() const
+{
+    uint64_t v0 = v[0], v1 = v[1], v2 = v[2], v3 = v[3];
+
+    uint64_t t = tmp | (((uint64_t)count) << 56);
+
+    v3 ^= t;
+    SIPROUND;
+    SIPROUND;
+    v0 ^= t;
+    v2 ^= 0xFF;
+    SIPROUND;
+    SIPROUND;
+    SIPROUND;
+    SIPROUND;
+    return v0 ^ v1 ^ v2 ^ v3;
+}
+
+uint64_t SipHashUint256(uint64_t k0, uint64_t k1, const uint256& val)
+{
+    /* Specialized implementation for efficiency */
+    uint64_t d = val.GetUint64(0);
+
+    uint64_t v0 = 0x736f6d6570736575ULL ^ k0;
+    uint64_t v1 = 0x646f72616e646f6dULL ^ k1;
+    uint64_t v2 = 0x6c7967656e657261ULL ^ k0;
+    uint64_t v3 = 0x7465646279746573ULL ^ k1 ^ d;
+
+    SIPROUND;
+    SIPROUND;
+    v0 ^= d;
+    d = val.GetUint64(1);
+    v3 ^= d;
+    SIPROUND;
+    SIPROUND;
+    v0 ^= d;
+    d = val.GetUint64(2);
+    v3 ^= d;
+    SIPROUND;
+    SIPROUND;
+    v0 ^= d;
+    d = val.GetUint64(3);
+    v3 ^= d;
+    SIPROUND;
+    SIPROUND;
+    v0 ^= d;
+    v3 ^= ((uint64_t)4) << 59;
+    SIPROUND;
+    SIPROUND;
+    v0 ^= ((uint64_t)4) << 59;
+    v2 ^= 0xFF;
+    SIPROUND;
+    SIPROUND;
+    SIPROUND;
+    SIPROUND;
+    return v0 ^ v1 ^ v2 ^ v3;
+}
+
+uint64_t SipHashUint256Extra(uint64_t k0, uint64_t k1, const uint256& val, uint32_t extra)
+{
+    /* Specialized implementation for efficiency */
+    uint64_t d = val.GetUint64(0);
+
+    uint64_t v0 = 0x736f6d6570736575ULL ^ k0;
+    uint64_t v1 = 0x646f72616e646f6dULL ^ k1;
+    uint64_t v2 = 0x6c7967656e657261ULL ^ k0;
+    uint64_t v3 = 0x7465646279746573ULL ^ k1 ^ d;
+
+    SIPROUND;
+    SIPROUND;
+    v0 ^= d;
+    d = val.GetUint64(1);
+    v3 ^= d;
+    SIPROUND;
+    SIPROUND;
+    v0 ^= d;
+    d = val.GetUint64(2);
+    v3 ^= d;
+    SIPROUND;
+    SIPROUND;
+    v0 ^= d;
+    d = val.GetUint64(3);
+    v3 ^= d;
+    SIPROUND;
+    SIPROUND;
+    v0 ^= d;
+    d = (((uint64_t)36) << 56) | extra;
+    v3 ^= d;
+    SIPROUND;
+    SIPROUND;
+    v0 ^= d;
+    v2 ^= 0xFF;
+    SIPROUND;
+    SIPROUND;
+    SIPROUND;
+    SIPROUND;
+    return v0 ^ v1 ^ v2 ^ v3;
+}
diff --git a/src/crypto/siphash.h b/src/crypto/siphash.h
new file mode 100644
index 000000000000..b312f913f936
--- /dev/null
+++ b/src/crypto/siphash.h
@@ -0,0 +1,47 @@
+// Copyright (c) 2016-2018 The Bitcoin Core developers
+// Distributed under the MIT software license, see the accompanying
+// file COPYING or http://www.opensource.org/licenses/mit-license.php.
+
+#ifndef BITCOIN_CRYPTO_SIPHASH_H
+#define BITCOIN_CRYPTO_SIPHASH_H
+
+#include <stdint.h>
+
+#include <uint256.h>
+
+/** SipHash-2-4 */
+class CSipHasher
+{
+private:
+    uint64_t v[4];
+    uint64_t tmp;
+    int count;
+
+public:
+    /** Construct a SipHash calculator initialized with 128-bit key (k0, k1) */
+    CSipHasher(uint64_t k0, uint64_t k1);
+    /** Hash a 64-bit integer worth of data
+     *  It is treated as if this was the little-endian interpretation of 8 bytes.
+     *  This function can only be used when a multiple of 8 bytes have been written so far.
+     */
+    CSipHasher& Write(uint64_t data);
+    /** Hash arbitrary bytes. */
+    CSipHasher& Write(const unsigned char* data, size_t size);
+    /** Compute the 64-bit SipHash-2-4 of the data written so far. The object remains untouched. */
+    uint64_t Finalize() const;
+};
+
+/** Optimized SipHash-2-4 implementation for uint256.
+ *
+ *  It is identical to:
+ *    SipHasher(k0, k1)
+ *      .Write(val.GetUint64(0))
+ *      .Write(val.GetUint64(1))
+ *      .Write(val.GetUint64(2))
+ *      .Write(val.GetUint64(3))
+ *      .Finalize()
+ */
+uint64_t SipHashUint256(uint64_t k0, uint64_t k1, const uint256& val);
+uint64_t SipHashUint256Extra(uint64_t k0, uint64_t k1, const uint256& val, uint32_t extra);
+
+#endif // BITCOIN_CRYPTO_SIPHASH_H
diff --git a/src/dash-cli.cpp b/src/dash-cli.cpp
index ca205fa940ea..7ea565af51c7 100644
--- a/src/dash-cli.cpp
+++ b/src/dash-cli.cpp
@@ -14,8 +14,8 @@
 #include <rpc/client.h>
 #include <rpc/protocol.h>
 #include <stacktraces.h>
-#include <util.h>
-#include <utilstrencodings.h>
+#include <util/system.h>
+#include <util/strencodings.h>
 
 #include <memory>
 #include <stdio.h>
diff --git a/src/dash-tx.cpp b/src/dash-tx.cpp
index 9e3a2807fd28..fd4152b1d7e3 100644
--- a/src/dash-tx.cpp
+++ b/src/dash-tx.cpp
@@ -17,9 +17,9 @@
 #include <script/script.h>
 #include <script/sign.h>
 #include <univalue.h>
-#include <util.h>
-#include <utilmoneystr.h>
-#include <utilstrencodings.h>
+#include <util/system.h>
+#include <util/moneystr.h>
+#include <util/strencodings.h>
 
 #include <memory>
 #include <stdio.h>
diff --git a/src/dashd.cpp b/src/dashd.cpp
index 1d5277470d28..a5e90b1b3d8b 100644
--- a/src/dashd.cpp
+++ b/src/dashd.cpp
@@ -15,11 +15,11 @@
 #include <rpc/server.h>
 #include <init.h>
 #include <noui.h>
-#include <util.h>
+#include <util/system.h>
 #include <httpserver.h>
 #include <httprpc.h>
-#include <utilstrencodings.h>
-#include <utilthreadnames.h>
+#include <util/strencodings.h>
+#include <util/threadnames.h>
 #include <walletinitinterface.h>
 #include <stacktraces.h>
 
diff --git a/src/dbwrapper.h b/src/dbwrapper.h
index c795054686e8..b90031245559 100644
--- a/src/dbwrapper.h
+++ b/src/dbwrapper.h
@@ -9,8 +9,8 @@
 #include <fs.h>
 #include <serialize.h>
 #include <streams.h>
-#include <util.h>
-#include <utilstrencodings.h>
+#include <util/system.h>
+#include <util/strencodings.h>
 #include <version.h>
 
 #include <typeindex>
diff --git a/src/evo/deterministicmns.h b/src/evo/deterministicmns.h
index 2e554203a78d..0b3e8ae63e63 100644
--- a/src/evo/deterministicmns.h
+++ b/src/evo/deterministicmns.h
@@ -508,7 +508,7 @@ class CDeterministicMNList
 
 private:
     template <typename T>
-    NODISCARD bool AddUniqueProperty(const CDeterministicMNCPtr& dmn, const T& v)
+    [[nodiscard]] bool AddUniqueProperty(const CDeterministicMNCPtr& dmn, const T& v)
     {
         static const T nullValue;
         if (v == nullValue) {
@@ -528,7 +528,7 @@ class CDeterministicMNList
         return true;
     }
     template <typename T>
-    NODISCARD bool DeleteUniqueProperty(const CDeterministicMNCPtr& dmn, const T& oldValue)
+    [[nodiscard]] bool DeleteUniqueProperty(const CDeterministicMNCPtr& dmn, const T& oldValue)
     {
         static const T nullValue;
         if (oldValue == nullValue) {
@@ -548,7 +548,7 @@ class CDeterministicMNList
         return true;
     }
     template <typename T>
-    NODISCARD bool UpdateUniqueProperty(const CDeterministicMNCPtr& dmn, const T& oldValue, const T& newValue)
+    [[nodiscard]] bool UpdateUniqueProperty(const CDeterministicMNCPtr& dmn, const T& oldValue, const T& newValue)
     {
         if (oldValue == newValue) {
             return true;
diff --git a/src/flat-database.h b/src/flat-database.h
index 3c863c8c1ae1..ad30d7bd58be 100644
--- a/src/flat-database.h
+++ b/src/flat-database.h
@@ -10,7 +10,7 @@
 #include <fs.h>
 #include <hash.h>
 #include <streams.h>
-#include <util.h>
+#include <util/system.h>
 
 /**
 *   Generic Dumping and Loading
diff --git a/src/governance/governance-classes.cpp b/src/governance/governance-classes.cpp
index 20fde2289073..e0bf7b9ccecb 100644
--- a/src/governance/governance-classes.cpp
+++ b/src/governance/governance-classes.cpp
@@ -10,7 +10,7 @@
 #include <primitives/transaction.h>
 #include <script/standard.h>
 #include <timedata.h>
-#include <utilstrencodings.h>
+#include <util/strencodings.h>
 #include <validation.h>
 
 #include <boost/algorithm/string.hpp>
diff --git a/src/governance/governance-validators.cpp b/src/governance/governance-validators.cpp
index ef780c6066d7..379771d59cd8 100644
--- a/src/governance/governance-validators.cpp
+++ b/src/governance/governance-validators.cpp
@@ -8,7 +8,7 @@
 #include <key_io.h>
 #include <timedata.h>
 #include <tinyformat.h>
-#include <utilstrencodings.h>
+#include <util/strencodings.h>
 
 #include <algorithm>
 
diff --git a/src/governance/governance-vote.cpp b/src/governance/governance-vote.cpp
index 448622ac6b32..4f8ad9086e6e 100644
--- a/src/governance/governance-vote.cpp
+++ b/src/governance/governance-vote.cpp
@@ -9,7 +9,7 @@
 #include <masternode/masternode-sync.h>
 #include <messagesigner.h>
 #include <net.h>
-#include <util.h>
+#include <util/system.h>
 
 #include <evo/deterministicmns.h>
 
diff --git a/src/hash.cpp b/src/hash.cpp
index ee0281f9eb44..b54214f8ff1c 100644
--- a/src/hash.cpp
+++ b/src/hash.cpp
@@ -77,171 +77,3 @@ void BIP32Hash(const ChainCode &chainCode, unsigned int nChild, unsigned char he
     num[3] = (nChild >>  0) & 0xFF;
     CHMAC_SHA512(chainCode.begin(), chainCode.size()).Write(&header, 1).Write(data, 32).Write(num, 4).Finalize(output);
 }
-
-#define ROTL(x, b) (uint64_t)(((x) << (b)) | ((x) >> (64 - (b))))
-
-#define SIPROUND do { \
-    v0 += v1; v1 = ROTL(v1, 13); v1 ^= v0; \
-    v0 = ROTL(v0, 32); \
-    v2 += v3; v3 = ROTL(v3, 16); v3 ^= v2; \
-    v0 += v3; v3 = ROTL(v3, 21); v3 ^= v0; \
-    v2 += v1; v1 = ROTL(v1, 17); v1 ^= v2; \
-    v2 = ROTL(v2, 32); \
-} while (0)
-
-CSipHasher::CSipHasher(uint64_t k0, uint64_t k1)
-{
-    v[0] = 0x736f6d6570736575ULL ^ k0;
-    v[1] = 0x646f72616e646f6dULL ^ k1;
-    v[2] = 0x6c7967656e657261ULL ^ k0;
-    v[3] = 0x7465646279746573ULL ^ k1;
-    count = 0;
-    tmp = 0;
-}
-
-CSipHasher& CSipHasher::Write(uint64_t data)
-{
-    uint64_t v0 = v[0], v1 = v[1], v2 = v[2], v3 = v[3];
-
-    assert(count % 8 == 0);
-
-    v3 ^= data;
-    SIPROUND;
-    SIPROUND;
-    v0 ^= data;
-
-    v[0] = v0;
-    v[1] = v1;
-    v[2] = v2;
-    v[3] = v3;
-
-    count += 8;
-    return *this;
-}
-
-CSipHasher& CSipHasher::Write(const unsigned char* data, size_t size)
-{
-    uint64_t v0 = v[0], v1 = v[1], v2 = v[2], v3 = v[3];
-    uint64_t t = tmp;
-    int c = count;
-
-    while (size--) {
-        t |= ((uint64_t)(*(data++))) << (8 * (c % 8));
-        c++;
-        if ((c & 7) == 0) {
-            v3 ^= t;
-            SIPROUND;
-            SIPROUND;
-            v0 ^= t;
-            t = 0;
-        }
-    }
-
-    v[0] = v0;
-    v[1] = v1;
-    v[2] = v2;
-    v[3] = v3;
-    count = c;
-    tmp = t;
-
-    return *this;
-}
-
-uint64_t CSipHasher::Finalize() const
-{
-    uint64_t v0 = v[0], v1 = v[1], v2 = v[2], v3 = v[3];
-
-    uint64_t t = tmp | (((uint64_t)count) << 56);
-
-    v3 ^= t;
-    SIPROUND;
-    SIPROUND;
-    v0 ^= t;
-    v2 ^= 0xFF;
-    SIPROUND;
-    SIPROUND;
-    SIPROUND;
-    SIPROUND;
-    return v0 ^ v1 ^ v2 ^ v3;
-}
-
-uint64_t SipHashUint256(uint64_t k0, uint64_t k1, const uint256& val)
-{
-    /* Specialized implementation for efficiency */
-    uint64_t d = val.GetUint64(0);
-
-    uint64_t v0 = 0x736f6d6570736575ULL ^ k0;
-    uint64_t v1 = 0x646f72616e646f6dULL ^ k1;
-    uint64_t v2 = 0x6c7967656e657261ULL ^ k0;
-    uint64_t v3 = 0x7465646279746573ULL ^ k1 ^ d;
-
-    SIPROUND;
-    SIPROUND;
-    v0 ^= d;
-    d = val.GetUint64(1);
-    v3 ^= d;
-    SIPROUND;
-    SIPROUND;
-    v0 ^= d;
-    d = val.GetUint64(2);
-    v3 ^= d;
-    SIPROUND;
-    SIPROUND;
-    v0 ^= d;
-    d = val.GetUint64(3);
-    v3 ^= d;
-    SIPROUND;
-    SIPROUND;
-    v0 ^= d;
-    v3 ^= ((uint64_t)4) << 59;
-    SIPROUND;
-    SIPROUND;
-    v0 ^= ((uint64_t)4) << 59;
-    v2 ^= 0xFF;
-    SIPROUND;
-    SIPROUND;
-    SIPROUND;
-    SIPROUND;
-    return v0 ^ v1 ^ v2 ^ v3;
-}
-
-uint64_t SipHashUint256Extra(uint64_t k0, uint64_t k1, const uint256& val, uint32_t extra)
-{
-    /* Specialized implementation for efficiency */
-    uint64_t d = val.GetUint64(0);
-
-    uint64_t v0 = 0x736f6d6570736575ULL ^ k0;
-    uint64_t v1 = 0x646f72616e646f6dULL ^ k1;
-    uint64_t v2 = 0x6c7967656e657261ULL ^ k0;
-    uint64_t v3 = 0x7465646279746573ULL ^ k1 ^ d;
-
-    SIPROUND;
-    SIPROUND;
-    v0 ^= d;
-    d = val.GetUint64(1);
-    v3 ^= d;
-    SIPROUND;
-    SIPROUND;
-    v0 ^= d;
-    d = val.GetUint64(2);
-    v3 ^= d;
-    SIPROUND;
-    SIPROUND;
-    v0 ^= d;
-    d = val.GetUint64(3);
-    v3 ^= d;
-    SIPROUND;
-    SIPROUND;
-    v0 ^= d;
-    d = (((uint64_t)36) << 56) | extra;
-    v3 ^= d;
-    SIPROUND;
-    SIPROUND;
-    v0 ^= d;
-    v2 ^= 0xFF;
-    SIPROUND;
-    SIPROUND;
-    SIPROUND;
-    SIPROUND;
-    return v0 ^ v1 ^ v2 ^ v3;
-}
diff --git a/src/hash.h b/src/hash.h
index 1a6401e67298..d860aeee1ca3 100644
--- a/src/hash.h
+++ b/src/hash.h
@@ -264,41 +264,6 @@ unsigned int MurmurHash3(unsigned int nHashSeed, Span<const unsigned char> vData
 
 void BIP32Hash(const ChainCode &chainCode, unsigned int nChild, unsigned char header, const unsigned char data[32], unsigned char output[64]);
 
-/** SipHash-2-4 */
-class CSipHasher
-{
-private:
-    uint64_t v[4];
-    uint64_t tmp;
-    int count;
-
-public:
-    /** Construct a SipHash calculator initialized with 128-bit key (k0, k1) */
-    CSipHasher(uint64_t k0, uint64_t k1);
-    /** Hash a 64-bit integer worth of data
-     *  It is treated as if this was the little-endian interpretation of 8 bytes.
-     *  This function can only be used when a multiple of 8 bytes have been written so far.
-     */
-    CSipHasher& Write(uint64_t data);
-    /** Hash arbitrary bytes. */
-    CSipHasher& Write(const unsigned char* data, size_t size);
-    /** Compute the 64-bit SipHash-2-4 of the data written so far. The object remains untouched. */
-    uint64_t Finalize() const;
-};
-
-/** Optimized SipHash-2-4 implementation for uint256.
- *
- *  It is identical to:
- *    SipHasher(k0, k1)
- *      .Write(val.GetUint64(0))
- *      .Write(val.GetUint64(1))
- *      .Write(val.GetUint64(2))
- *      .Write(val.GetUint64(3))
- *      .Finalize()
- */
-uint64_t SipHashUint256(uint64_t k0, uint64_t k1, const uint256& val);
-uint64_t SipHashUint256Extra(uint64_t k0, uint64_t k1, const uint256& val, uint32_t extra);
-
 /* ----------- Dash Hash ------------------------------------------------ */
 template<typename T1>
 inline uint256 HashX11(const T1 pbegin, const T1 pend)
diff --git a/src/hdchain.cpp b/src/hdchain.cpp
index 343cf689e113..192c8dc2e1e5 100644
--- a/src/hdchain.cpp
+++ b/src/hdchain.cpp
@@ -6,8 +6,8 @@
 #include <hdchain.h>
 #include <key_io.h>
 #include <tinyformat.h>
-#include <util.h>
-#include <utilstrencodings.h>
+#include <util/system.h>
+#include <util/strencodings.h>
 
 bool CHDChain::SetNull()
 {
diff --git a/src/httprpc.cpp b/src/httprpc.cpp
index 8be07274d7c4..4ad50ce8bbef 100644
--- a/src/httprpc.cpp
+++ b/src/httprpc.cpp
@@ -11,8 +11,8 @@
 #include <rpc/server.h>
 #include <random.h>
 #include <sync.h>
-#include <util.h>
-#include <utilstrencodings.h>
+#include <util/system.h>
+#include <util/strencodings.h>
 #include <ui_interface.h>
 #include <crypto/hmac_sha256.h>
 #include <stdio.h>
diff --git a/src/httpserver.cpp b/src/httpserver.cpp
index 63051934282e..65ede63eab44 100644
--- a/src/httpserver.cpp
+++ b/src/httpserver.cpp
@@ -7,9 +7,9 @@
 #include <init.h>
 #include <chainparamsbase.h>
 #include <compat.h>
-#include <util.h>
-#include <utilstrencodings.h>
-#include <utilthreadnames.h>
+#include <util/system.h>
+#include <util/strencodings.h>
+#include <util/threadnames.h>
 #include <netbase.h>
 #include <rpc/protocol.h> // For HTTP status codes
 #include <sync.h>
@@ -667,15 +667,3 @@ void UnregisterHTTPHandler(const std::string &prefix, bool exactMatch)
         pathHandlers.erase(i);
     }
 }
-
-std::string urlDecode(const std::string &urlEncoded) {
-    std::string res;
-    if (!urlEncoded.empty()) {
-        char *decoded = evhttp_uridecode(urlEncoded.c_str(), false, nullptr);
-        if (decoded) {
-            res = std::string(decoded);
-            free(decoded);
-        }
-    }
-    return res;
-}
diff --git a/src/httpserver.h b/src/httpserver.h
index fdb525a58a93..50dffdb577ae 100644
--- a/src/httpserver.h
+++ b/src/httpserver.h
@@ -148,6 +148,4 @@ class HTTPEvent
     struct event* ev;
 };
 
-std::string urlDecode(const std::string &urlEncoded);
-
 #endif // BITCOIN_HTTPSERVER_H
diff --git a/src/index/txindex.cpp b/src/index/txindex.cpp
index 82309b60d488..3afc3825cc7f 100644
--- a/src/index/txindex.cpp
+++ b/src/index/txindex.cpp
@@ -7,7 +7,7 @@
 #include <init.h>
 #include <tinyformat.h>
 #include <ui_interface.h>
-#include <util.h>
+#include <util/system.h>
 #include <validation.h>
 #include <warnings.h>
 
diff --git a/src/init.cpp b/src/init.cpp
index dc5510bd2c7d..d1b32f4f6053 100644
--- a/src/init.cpp
+++ b/src/init.cpp
@@ -39,15 +39,17 @@
 #include <script/standard.h>
 #include <script/sigcache.h>
 #include <scheduler.h>
-#include <utilthreadnames.h>
+#include <util/threadnames.h>
 #include <timedata.h>
 #include <txdb.h>
 #include <txmempool.h>
 #include <torcontrol.h>
 #include <ui_interface.h>
-#include <util.h>
-#include <utilasmap.h>
-#include <utilmoneystr.h>
+#include <util/asmap.h>
+#include <util/error.h>
+#include <util/moneystr.h>
+#include <util/system.h>
+#include <util/validation.h>
 #include <validationinterface.h>
 
 #include <masternode/activemasternode.h>
diff --git a/src/init.h b/src/init.h
index 17ce661e3045..48c98eae75bb 100644
--- a/src/init.h
+++ b/src/init.h
@@ -8,7 +8,7 @@
 
 #include <memory>
 #include <string>
-#include <util.h>
+#include <util/system.h>
 
 class CScheduler;
 class CWallet;
diff --git a/src/interfaces/handler.cpp b/src/interfaces/handler.cpp
index 1443fe9f18ff..2f849b806fc7 100644
--- a/src/interfaces/handler.cpp
+++ b/src/interfaces/handler.cpp
@@ -4,7 +4,7 @@
 
 #include <interfaces/handler.h>
 
-#include <util.h>
+#include <util/system.h>
 
 #include <boost/signals2/connection.hpp>
 #include <memory>
diff --git a/src/interfaces/node.cpp b/src/interfaces/node.cpp
index b21ab12cb96e..99b68d6786af 100644
--- a/src/interfaces/node.cpp
+++ b/src/interfaces/node.cpp
@@ -27,7 +27,7 @@
 #include <sync.h>
 #include <txmempool.h>
 #include <ui_interface.h>
-#include <util.h>
+#include <util/system.h>
 #include <validation.h>
 #include <warnings.h>
 
diff --git a/src/keepass.cpp b/src/keepass.cpp
index e3210bf244e4..e46cdf53da2f 100644
--- a/src/keepass.cpp
+++ b/src/keepass.cpp
@@ -15,8 +15,8 @@
 #include <script/script.h>
 #include <script/standard.h>
 
-#include <util.h>
-#include <utilstrencodings.h>
+#include <util/system.h>
+#include <util/strencodings.h>
 
 #include <event2/event.h>
 #include <event2/http.h>
diff --git a/src/key_io.cpp b/src/key_io.cpp
index da1315ebf60d..11882257df9a 100644
--- a/src/key_io.cpp
+++ b/src/key_io.cpp
@@ -7,7 +7,7 @@
 #include <base58.h>
 #include <bech32.h>
 #include <script/script.h>
-#include <utilstrencodings.h>
+#include <util/strencodings.h>
 
 #include <boost/variant/apply_visitor.hpp>
 #include <boost/variant/static_visitor.hpp>
diff --git a/src/keystore.cpp b/src/keystore.cpp
index 1afa14379cb7..fe28ea7a7938 100644
--- a/src/keystore.cpp
+++ b/src/keystore.cpp
@@ -5,7 +5,7 @@
 
 #include <keystore.h>
 
-#include <util.h>
+#include <util/system.h>
 
 bool CBasicKeyStore::GetPubKey(const CKeyID &address, CPubKey &vchPubKeyOut) const
 {
diff --git a/src/llmq/quorums_chainlocks.cpp b/src/llmq/quorums_chainlocks.cpp
index 07855bb3c1d2..1e9b192a94ad 100644
--- a/src/llmq/quorums_chainlocks.cpp
+++ b/src/llmq/quorums_chainlocks.cpp
@@ -14,6 +14,7 @@
 #include <scheduler.h>
 #include <spork.h>
 #include <txmempool.h>
+#include <util/validation.h>
 
 namespace llmq
 {
diff --git a/src/llmq/quorums_instantsend.cpp b/src/llmq/quorums_instantsend.cpp
index 0aa67e67f825..40d08d4832a7 100644
--- a/src/llmq/quorums_instantsend.cpp
+++ b/src/llmq/quorums_instantsend.cpp
@@ -17,6 +17,7 @@
 #include <net_processing.h>
 #include <spork.h>
 #include <validation.h>
+#include <util/validation.h>
 
 #include <cxxtimer.hpp>
 
diff --git a/src/logging.cpp b/src/logging.cpp
index e430ebc9219f..db0a4c043bbc 100644
--- a/src/logging.cpp
+++ b/src/logging.cpp
@@ -4,9 +4,9 @@
 // file COPYING or http://www.opensource.org/licenses/mit-license.php.
 
 #include <logging.h>
-#include <util.h>
-#include <utilthreadnames.h>
-#include <utiltime.h>
+#include <util/system.h>
+#include <util/threadnames.h>
+#include <util/time.h>
 
 #include <mutex>
 
diff --git a/src/logging/timer.h b/src/logging/timer.h
index ca34aa08ac1d..db14632b8e1c 100644
--- a/src/logging/timer.h
+++ b/src/logging/timer.h
@@ -8,7 +8,7 @@
 
 #include <logging.h>
 #include <sync.h>
-#include <utiltime.h>
+#include <util/time.h>
 
 #include <chrono>
 #include <string>
diff --git a/src/merkleblock.cpp b/src/merkleblock.cpp
index 0731ceba8a5b..5d592e096adb 100644
--- a/src/merkleblock.cpp
+++ b/src/merkleblock.cpp
@@ -7,7 +7,7 @@
 
 #include <hash.h>
 #include <consensus/consensus.h>
-#include <utilstrencodings.h>
+#include <util/strencodings.h>
 
 
 std::vector<unsigned char> BitsToBytes(const std::vector<bool>& bits)
diff --git a/src/messagesigner.cpp b/src/messagesigner.cpp
index 3aedcc127171..7ee762ea675f 100644
--- a/src/messagesigner.cpp
+++ b/src/messagesigner.cpp
@@ -7,7 +7,7 @@
 #include <validation.h> // For strMessageMagic
 #include <messagesigner.h>
 #include <tinyformat.h>
-#include <utilstrencodings.h>
+#include <util/strencodings.h>
 
 bool CMessageSigner::GetKeysFromSecret(const std::string& strSecret, CKey& keyRet, CPubKey& pubkeyRet)
 {
diff --git a/src/miner.cpp b/src/miner.cpp
index 22b0b272ee1d..811b958117cb 100644
--- a/src/miner.cpp
+++ b/src/miner.cpp
@@ -22,8 +22,9 @@
 #include <primitives/transaction.h>
 #include <script/standard.h>
 #include <timedata.h>
-#include <util.h>
-#include <utilmoneystr.h>
+#include <util/system.h>
+#include <util/moneystr.h>
+#include <util/validation.h>
 #include <masternode/masternode-payments.h>
 #include <masternode/masternode-sync.h>
 #include <validationinterface.h>
diff --git a/src/net.cpp b/src/net.cpp
index 3d8a1120da4e..50c7aaa509b6 100644
--- a/src/net.cpp
+++ b/src/net.cpp
@@ -20,7 +20,7 @@
 #include <netbase.h>
 #include <scheduler.h>
 #include <ui_interface.h>
-#include <utilstrencodings.h>
+#include <util/strencodings.h>
 #include <validation.h>
 
 #include <masternode/masternode-meta.h>
diff --git a/src/net.h b/src/net.h
index b60692615fcd..33f500908a13 100644
--- a/src/net.h
+++ b/src/net.h
@@ -11,6 +11,7 @@
 #include <bloom.h>
 #include <compat.h>
 #include <fs.h>
+#include <crypto/siphash.h>
 #include <hash.h>
 #include <limitedmap.h>
 #include <netaddress.h>
@@ -21,7 +22,7 @@
 #include <streams.h>
 #include <sync.h>
 #include <uint256.h>
-#include <util.h>
+#include <util/system.h>
 #include <threadinterrupt.h>
 #include <consensus/params.h>
 
diff --git a/src/net_processing.cpp b/src/net_processing.cpp
index 4f430e279d84..df6d9f0ac4cf 100644
--- a/src/net_processing.cpp
+++ b/src/net_processing.cpp
@@ -28,9 +28,10 @@
 #include <index/txindex.h>
 #include <txmempool.h>
 #include <ui_interface.h>
-#include <util.h>
-#include <utilmoneystr.h>
-#include <utilstrencodings.h>
+#include <util/system.h>
+#include <util/moneystr.h>
+#include <util/strencodings.h>
+#include <util/validation.h>
 
 #include <memory>
 
diff --git a/src/netaddress.cpp b/src/netaddress.cpp
index 6058ec38e725..4d43550ba81b 100644
--- a/src/netaddress.cpp
+++ b/src/netaddress.cpp
@@ -10,9 +10,9 @@
 #include <hash.h>
 #include <prevector.h>
 #include <tinyformat.h>
-#include <utilasmap.h>
-#include <utilstrencodings.h>
-#include <utilstring.h>
+#include <util/asmap.h>
+#include <util/strencodings.h>
+#include <util/string.h>
 
 #include <algorithm>
 #include <array>
diff --git a/src/netaddress.h b/src/netaddress.h
index 2c1802aac809..1ca4933bdaba 100644
--- a/src/netaddress.h
+++ b/src/netaddress.h
@@ -15,8 +15,8 @@
 #include <serialize.h>
 #include <span.h>
 #include <tinyformat.h>
-#include <utilstrencodings.h>
-#include <utilstring.h>
+#include <util/strencodings.h>
+#include <util/string.h>
 
 #include <array>
 #include <cstdint>
diff --git a/src/netbase.cpp b/src/netbase.cpp
index d38a0655f2bb..e70159e6b2b8 100644
--- a/src/netbase.cpp
+++ b/src/netbase.cpp
@@ -10,8 +10,8 @@
 #include <uint256.h>
 #include <random.h>
 #include <tinyformat.h>
-#include <util.h>
-#include <utilstrencodings.h>
+#include <util/system.h>
+#include <util/strencodings.h>
 
 #include <atomic>
 #include <cstdint>
diff --git a/src/netfulfilledman.cpp b/src/netfulfilledman.cpp
index 71fcacaf0ee6..b144e936fb5b 100644
--- a/src/netfulfilledman.cpp
+++ b/src/netfulfilledman.cpp
@@ -5,7 +5,7 @@
 #include <chainparams.h>
 #include <init.h>
 #include <netfulfilledman.h>
-#include <util.h>
+#include <util/system.h>
 
 CNetFulfilledRequestManager netfulfilledman;
 
diff --git a/src/node/coinstats.cpp b/src/node/coinstats.cpp
index 87b9f47e08cd..641378d0e7fa 100644
--- a/src/node/coinstats.cpp
+++ b/src/node/coinstats.cpp
@@ -13,7 +13,7 @@
 #include <validation.h>
 #include <uint256.h>
 // #include <util/system.h>
-#include <util.h>
+#include <util/system.h>
 
 #include <map>
 
diff --git a/src/noui.cpp b/src/noui.cpp
index fddc3a4592df..7591eb991cb9 100644
--- a/src/noui.cpp
+++ b/src/noui.cpp
@@ -7,7 +7,7 @@
 #include <noui.h>
 
 #include <ui_interface.h>
-#include <util.h>
+#include <util/system.h>
 
 #include <cstdio>
 #include <stdint.h>
diff --git a/src/policy/fees.cpp b/src/policy/fees.cpp
index 5cc7bc41afd5..aa0daa512240 100644
--- a/src/policy/fees.cpp
+++ b/src/policy/fees.cpp
@@ -10,7 +10,7 @@
 #include <primitives/transaction.h>
 #include <streams.h>
 #include <txmempool.h>
-#include <util.h>
+#include <util/system.h>
 
 static constexpr double INF_FEERATE = 1e99;
 
diff --git a/src/policy/policy.cpp b/src/policy/policy.cpp
index cd9d16ff6746..5aecbc6b4303 100644
--- a/src/policy/policy.cpp
+++ b/src/policy/policy.cpp
@@ -10,8 +10,8 @@
 #include <validation.h>
 #include <coins.h>
 #include <tinyformat.h>
-#include <util.h>
-#include <utilstrencodings.h>
+#include <util/system.h>
+#include <util/strencodings.h>
 
 
 CAmount GetDustThreshold(const CTxOut& txout, const CFeeRate& dustRelayFeeIn)
diff --git a/src/primitives/block.cpp b/src/primitives/block.cpp
index 2e3e33349f97..38413aabbd5d 100644
--- a/src/primitives/block.cpp
+++ b/src/primitives/block.cpp
@@ -8,7 +8,7 @@
 #include <hash.h>
 #include <streams.h>
 #include <tinyformat.h>
-#include <utilstrencodings.h>
+#include <util/strencodings.h>
 #include <crypto/common.h>
 
 uint256 CBlockHeader::GetHash() const
diff --git a/src/primitives/transaction.cpp b/src/primitives/transaction.cpp
index 2348aadfebed..a2c8fcd92721 100644
--- a/src/primitives/transaction.cpp
+++ b/src/primitives/transaction.cpp
@@ -7,7 +7,7 @@
 
 #include <hash.h>
 #include <tinyformat.h>
-#include <utilstrencodings.h>
+#include <util/strencodings.h>
 
 std::string COutPoint::ToString() const
 {
diff --git a/src/protocol.cpp b/src/protocol.cpp
index 5d6ae80645a3..01d6bae98725 100644
--- a/src/protocol.cpp
+++ b/src/protocol.cpp
@@ -5,8 +5,8 @@
 
 #include <protocol.h>
 
-#include <util.h>
-#include <utilstrencodings.h>
+#include <util/system.h>
+#include <util/strencodings.h>
 
 #ifndef WIN32
 # include <arpa/inet.h>
diff --git a/src/qt/appearancewidget.cpp b/src/qt/appearancewidget.cpp
index 93f49e033dbb..358caba0548f 100644
--- a/src/qt/appearancewidget.cpp
+++ b/src/qt/appearancewidget.cpp
@@ -11,7 +11,7 @@
 #include <qt/appearancewidget.h>
 #include <qt/optionsmodel.h>
 
-#include <util.h>
+#include <util/system.h>
 
 #include <QComboBox>
 #include <QDataWidgetMapper>
diff --git a/src/qt/bantablemodel.cpp b/src/qt/bantablemodel.cpp
index c0563de30065..4645f5da53e9 100644
--- a/src/qt/bantablemodel.cpp
+++ b/src/qt/bantablemodel.cpp
@@ -10,7 +10,7 @@
 
 #include <interfaces/node.h>
 #include <sync.h>
-#include <utiltime.h>
+#include <util/time.h>
 
 #include <QDebug>
 #include <QList>
diff --git a/src/qt/bitcoingui.cpp b/src/qt/bitcoingui.cpp
index e7e92d375c57..1f87618c5f3a 100644
--- a/src/qt/bitcoingui.cpp
+++ b/src/qt/bitcoingui.cpp
@@ -33,7 +33,7 @@
 #include <interfaces/handler.h>
 #include <interfaces/node.h>
 #include <ui_interface.h>
-#include <util.h>
+#include <util/system.h>
 #include <qt/masternodelist.h>
 
 #include <iostream>
diff --git a/src/qt/clientmodel.cpp b/src/qt/clientmodel.cpp
index 8154f4048bd6..3b644e1b20dc 100644
--- a/src/qt/clientmodel.cpp
+++ b/src/qt/clientmodel.cpp
@@ -22,7 +22,7 @@
 #include <net.h>
 #include <txmempool.h>
 #include <ui_interface.h>
-#include <util.h>
+#include <util/system.h>
 #include <warnings.h>
 
 #include <stdint.h>
diff --git a/src/qt/dash.cpp b/src/qt/dash.cpp
index 527c5bde899c..21efd607afb0 100644
--- a/src/qt/dash.cpp
+++ b/src/qt/dash.cpp
@@ -34,7 +34,7 @@
 #include <stacktraces.h>
 #include <ui_interface.h>
 #include <uint256.h>
-#include <util.h>
+#include <util/system.h>
 #include <warnings.h>
 
 #include <walletinitinterface.h>
diff --git a/src/qt/guiutil.cpp b/src/qt/guiutil.cpp
index 5ebb0ab9ea5e..9f7920527a76 100644
--- a/src/qt/guiutil.cpp
+++ b/src/qt/guiutil.cpp
@@ -23,7 +23,7 @@
 #include <script/script.h>
 #include <script/standard.h>
 #include <ui_interface.h>
-#include <util.h>
+#include <util/system.h>
 
 #ifdef WIN32
 #ifdef _WIN32_WINNT
diff --git a/src/qt/intro.cpp b/src/qt/intro.cpp
index c6b8758e9dd2..ce5250446891 100644
--- a/src/qt/intro.cpp
+++ b/src/qt/intro.cpp
@@ -14,7 +14,7 @@
 #include <qt/guiutil.h>
 
 #include <interfaces/node.h>
-#include <util.h>
+#include <util/system.h>
 
 #include <QFileDialog>
 #include <QSettings>
diff --git a/src/qt/masternodelist.h b/src/qt/masternodelist.h
index 341364ac3bef..3b0ab784f0ee 100644
--- a/src/qt/masternodelist.h
+++ b/src/qt/masternodelist.h
@@ -3,7 +3,7 @@
 
 #include <primitives/transaction.h>
 #include <sync.h>
-#include <util.h>
+#include <util/system.h>
 
 #include <QMenu>
 #include <QTimer>
diff --git a/src/qt/networkstyle.cpp b/src/qt/networkstyle.cpp
index 647db3bec77e..639edda518b7 100644
--- a/src/qt/networkstyle.cpp
+++ b/src/qt/networkstyle.cpp
@@ -10,7 +10,7 @@
 
 #include <chainparams.h>
 #include <tinyformat.h>
-#include <util.h>
+#include <util/system.h>
 
 #include <QApplication>
 
diff --git a/src/qt/paymentrequestplus.cpp b/src/qt/paymentrequestplus.cpp
index 61d0e2517b8a..28b23f8b4e85 100644
--- a/src/qt/paymentrequestplus.cpp
+++ b/src/qt/paymentrequestplus.cpp
@@ -10,7 +10,7 @@
 #include <qt/paymentrequestplus.h>
 
 #include <script/script.h>
-#include <util.h>
+#include <util/system.h>
 
 #include <stdexcept>
 
diff --git a/src/qt/paymentserver.cpp b/src/qt/paymentserver.cpp
index ebd6a8550193..249910a957c0 100644
--- a/src/qt/paymentserver.cpp
+++ b/src/qt/paymentserver.cpp
@@ -15,7 +15,7 @@
 #include <policy/policy.h>
 #include <key_io.h>
 #include <ui_interface.h>
-#include <util.h>
+#include <util/system.h>
 
 #include <cstdlib>
 #include <memory>
diff --git a/src/qt/rpcconsole.cpp b/src/qt/rpcconsole.cpp
index 1c379d424be0..24696d966c93 100644
--- a/src/qt/rpcconsole.cpp
+++ b/src/qt/rpcconsole.cpp
@@ -20,7 +20,7 @@
 #include <netbase.h>
 #include <rpc/server.h>
 #include <rpc/client.h>
-#include <util.h>
+#include <util/system.h>
 
 #include <openssl/crypto.h>
 
diff --git a/src/qt/signverifymessagedialog.cpp b/src/qt/signverifymessagedialog.cpp
index 1a5c20eec728..e996bae1bd8a 100644
--- a/src/qt/signverifymessagedialog.cpp
+++ b/src/qt/signverifymessagedialog.cpp
@@ -12,8 +12,9 @@
 
 #include <init.h>
 #include <key_io.h>
-#include <utilstrencodings.h>
-#include <validation.h> // For strMessageMagic
+#include <util/strencodings.h>
+#include <util/validation.h> // For strMessageMagic
+#include <validation.h>
 
 #include <string>
 #include <vector>
diff --git a/src/qt/splashscreen.cpp b/src/qt/splashscreen.cpp
index 80c46d1eabe7..67126ee2997b 100644
--- a/src/qt/splashscreen.cpp
+++ b/src/qt/splashscreen.cpp
@@ -18,7 +18,7 @@
 #include <interfaces/handler.h>
 #include <interfaces/node.h>
 #include <interfaces/wallet.h>
-#include <util.h>
+#include <util/system.h>
 #include <ui_interface.h>
 #include <version.h>
 
diff --git a/src/qt/test/paymentservertests.cpp b/src/qt/test/paymentservertests.cpp
index ca549ef36af5..b31496dc93d2 100644
--- a/src/qt/test/paymentservertests.cpp
+++ b/src/qt/test/paymentservertests.cpp
@@ -13,8 +13,8 @@
 #include <random.h>
 #include <script/script.h>
 #include <script/standard.h>
-#include <util.h>
-#include <utilstrencodings.h>
+#include <util/system.h>
+#include <util/strencodings.h>
 
 #include <openssl/x509.h>
 #include <openssl/x509_vfy.h>
diff --git a/src/qt/test/rpcnestedtests.cpp b/src/qt/test/rpcnestedtests.cpp
index 74799933b1b2..388c5dfa4349 100644
--- a/src/qt/test/rpcnestedtests.cpp
+++ b/src/qt/test/rpcnestedtests.cpp
@@ -14,7 +14,7 @@
 #include <qt/rpcconsole.h>
 #include <test/test_dash.h>
 #include <univalue.h>
-#include <util.h>
+#include <util/system.h>
 
 #include <llmq/quorums_init.h>
 
diff --git a/src/qt/test/test_main.cpp b/src/qt/test/test_main.cpp
index 2e9750ce81de..c68f8ee60de4 100644
--- a/src/qt/test/test_main.cpp
+++ b/src/qt/test/test_main.cpp
@@ -9,7 +9,7 @@
 
 #include <chainparams.h>
 #include <qt/test/rpcnestedtests.h>
-#include <util.h>
+#include <util/system.h>
 #include <qt/test/uritests.h>
 #include <qt/test/compattests.h>
 #include <qt/test/trafficgraphdatatests.h>
diff --git a/src/qt/transactiondesc.cpp b/src/qt/transactiondesc.cpp
index 92837103b471..d99c1d61f497 100644
--- a/src/qt/transactiondesc.cpp
+++ b/src/qt/transactiondesc.cpp
@@ -16,7 +16,7 @@
 #include <validation.h>
 #include <script/script.h>
 #include <timedata.h>
-#include <util.h>
+#include <util/system.h>
 
 #include <stdint.h>
 #include <string>
diff --git a/src/qt/transactiontablemodel.cpp b/src/qt/transactiontablemodel.cpp
index 062f10a4a510..2a443e70a1a7 100644
--- a/src/qt/transactiontablemodel.cpp
+++ b/src/qt/transactiontablemodel.cpp
@@ -16,7 +16,7 @@
 #include <validation.h>
 #include <sync.h>
 #include <uint256.h>
-#include <util.h>
+#include <util/system.h>
 
 #include <QColor>
 #include <QDateTime>
diff --git a/src/qt/utilitydialog.cpp b/src/qt/utilitydialog.cpp
index 56be06def94b..c8f87bb7e5b2 100644
--- a/src/qt/utilitydialog.cpp
+++ b/src/qt/utilitydialog.cpp
@@ -21,7 +21,7 @@
 #include <clientversion.h>
 #include <init.h>
 #include <interfaces/node.h>
-#include <util.h>
+#include <util/system.h>
 
 #include <stdio.h>
 
diff --git a/src/qt/walletmodel.cpp b/src/qt/walletmodel.cpp
index 774e37554839..8e0b5215ddb4 100644
--- a/src/qt/walletmodel.cpp
+++ b/src/qt/walletmodel.cpp
@@ -16,7 +16,7 @@
 #include <interfaces/node.h>
 #include <key_io.h>
 #include <ui_interface.h>
-#include <util.h> // for GetBoolArg
+#include <util/system.h> // for GetBoolArg
 #include <wallet/coincontrol.h>
 #include <wallet/wallet.h>
 
diff --git a/src/qt/winshutdownmonitor.cpp b/src/qt/winshutdownmonitor.cpp
index bc9c287a57e6..1b9ddeae90ca 100644
--- a/src/qt/winshutdownmonitor.cpp
+++ b/src/qt/winshutdownmonitor.cpp
@@ -6,7 +6,7 @@
 
 #if defined(Q_OS_WIN)
 #include <init.h>
-#include <util.h>
+#include <util/system.h>
 
 #include <windows.h>
 
diff --git a/src/random.cpp b/src/random.cpp
index 61c21f040f3d..fee378f71577 100644
--- a/src/random.cpp
+++ b/src/random.cpp
@@ -13,7 +13,7 @@
 #endif
 #include <logging.h>  // for LogPrint()
 #include <sync.h>     // for WAIT_LOCK
-#include <utiltime.h> // for GetTime()
+#include <util/time.h> // for GetTime()
 
 #include <stdlib.h>
 #include <chrono>
@@ -35,7 +35,7 @@
 #include <sys/random.h>
 #endif
 #ifdef HAVE_SYSCTL_ARND
-#include <utilstrencodings.h> // for ARRAYLEN
+#include <util/strencodings.h> // for ARRAYLEN
 #include <sys/sysctl.h>
 #endif
 
diff --git a/src/rest.cpp b/src/rest.cpp
index a3212c534074..f355ffcf3e06 100644
--- a/src/rest.cpp
+++ b/src/rest.cpp
@@ -16,7 +16,7 @@
 #include <streams.h>
 #include <sync.h>
 #include <txmempool.h>
-#include <utilstrencodings.h>
+#include <util/strencodings.h>
 #include <validation.h>
 #include <version.h>
 
diff --git a/src/rpc/blockchain.cpp b/src/rpc/blockchain.cpp
index baa8e0d96c05..85bd57ec934a 100644
--- a/src/rpc/blockchain.cpp
+++ b/src/rpc/blockchain.cpp
@@ -23,8 +23,9 @@
 #include <sync.h>
 #include <txdb.h>
 #include <txmempool.h>
-#include <util.h>
-#include <utilstrencodings.h>
+#include <util/system.h>
+#include <util/strencodings.h>
+#include <util/validation.h>
 #include <hash.h>
 #include <validationinterface.h>
 #include <warnings.h>
diff --git a/src/rpc/client.cpp b/src/rpc/client.cpp
index 9c20f6d4fd54..f77f6bf254df 100644
--- a/src/rpc/client.cpp
+++ b/src/rpc/client.cpp
@@ -6,7 +6,7 @@
 
 #include <rpc/client.h>
 #include <rpc/protocol.h>
-#include <util.h>
+#include <util/system.h>
 
 #include <set>
 #include <stdint.h>
diff --git a/src/rpc/coinjoin.cpp b/src/rpc/coinjoin.cpp
index c7c18a632641..bccf9315fe21 100644
--- a/src/rpc/coinjoin.cpp
+++ b/src/rpc/coinjoin.cpp
@@ -10,7 +10,7 @@
 #endif // ENABLE_WALLET
 #include <coinjoin/coinjoin-server.h>
 #include <rpc/server.h>
-#include <utilstrencodings.h>
+#include <util/strencodings.h>
 
 #include <univalue.h>
 
diff --git a/src/rpc/governance.cpp b/src/rpc/governance.cpp
index 1e6ca52d2294..3107eefd103a 100644
--- a/src/rpc/governance.cpp
+++ b/src/rpc/governance.cpp
@@ -16,7 +16,7 @@
 #include <messagesigner.h>
 #include <net.h>
 #include <rpc/server.h>
-#include <util.h>
+#include <util/system.h>
 #include <validation.h>
 #include <wallet/rpcwallet.h>
 #ifdef ENABLE_WALLET
diff --git a/src/rpc/mining.cpp b/src/rpc/mining.cpp
index 188354e528a0..80219152bd33 100644
--- a/src/rpc/mining.cpp
+++ b/src/rpc/mining.cpp
@@ -12,7 +12,6 @@
 #include <consensus/validation.h>
 #include <core_io.h>
 #include <init.h>
-#include <validation.h>
 #include <key_io.h>
 #include <miner.h>
 #include <net.h>
@@ -22,8 +21,11 @@
 #include <rpc/mining.h>
 #include <rpc/server.h>
 #include <txmempool.h>
-#include <util.h>
-#include <utilstrencodings.h>
+#include <util/fees.h>
+#include <util/strencodings.h>
+#include <util/system.h>
+#include <util/validation.h>
+#include <validation.h>
 #include <validationinterface.h>
 #include <warnings.h>
 
diff --git a/src/rpc/misc.cpp b/src/rpc/misc.cpp
index 5b05b509931d..9db82bc8ea59 100644
--- a/src/rpc/misc.cpp
+++ b/src/rpc/misc.cpp
@@ -19,9 +19,10 @@
 #include <rpc/util.h>
 #include <timedata.h>
 #include <txmempool.h>
-#include <util.h>
-#include <utilstrencodings.h>
+#include <util/system.h>
+#include <util/strencodings.h>
 #include <validation.h>
+#include <util/validation.h>
 #ifdef ENABLE_WALLET
 #include <wallet/rpcwallet.h>
 #include <wallet/wallet.h>
diff --git a/src/rpc/net.cpp b/src/rpc/net.cpp
index 6e3bee29f934..344fb2bb71b6 100644
--- a/src/rpc/net.cpp
+++ b/src/rpc/net.cpp
@@ -17,8 +17,8 @@
 #include <sync.h>
 #include <timedata.h>
 #include <ui_interface.h>
-#include <util.h>
-#include <utilstrencodings.h>
+#include <util/system.h>
+#include <util/strencodings.h>
 #include <version.h>
 #include <warnings.h>
 
diff --git a/src/rpc/protocol.cpp b/src/rpc/protocol.cpp
index d57eea569e5e..6efdfe646955 100644
--- a/src/rpc/protocol.cpp
+++ b/src/rpc/protocol.cpp
@@ -8,9 +8,9 @@
 
 #include <random.h>
 #include <tinyformat.h>
-#include <util.h>
-#include <utilstrencodings.h>
-#include <utiltime.h>
+#include <util/system.h>
+#include <util/strencodings.h>
+#include <util/time.h>
 #include <version.h>
 
 /**
diff --git a/src/rpc/rawtransaction.cpp b/src/rpc/rawtransaction.cpp
index a5ccbb7c0fed..05f1477754c4 100644
--- a/src/rpc/rawtransaction.cpp
+++ b/src/rpc/rawtransaction.cpp
@@ -26,7 +26,8 @@
 #include <script/standard.h>
 #include <txmempool.h>
 #include <uint256.h>
-#include <utilstrencodings.h>
+#include <util/validation.h>
+#include <util/strencodings.h>
 #ifdef ENABLE_WALLET
 #include <wallet/rpcwallet.h>
 #endif
diff --git a/src/rpc/rpcevo.cpp b/src/rpc/rpcevo.cpp
index bb6803b1005f..eda7a313d392 100644
--- a/src/rpc/rpcevo.cpp
+++ b/src/rpc/rpcevo.cpp
@@ -10,7 +10,8 @@
 #include <messagesigner.h>
 #include <rpc/server.h>
 #include <txmempool.h>
-#include <utilmoneystr.h>
+#include <util/moneystr.h>
+#include <util/validation.h>
 #include <validation.h>
 
 #ifdef ENABLE_WALLET
diff --git a/src/rpc/server.cpp b/src/rpc/server.cpp
index 2e7b6b66b2f9..caf2bee326a6 100644
--- a/src/rpc/server.cpp
+++ b/src/rpc/server.cpp
@@ -12,8 +12,8 @@
 #include <random.h>
 #include <sync.h>
 #include <ui_interface.h>
-#include <util.h>
-#include <utilstrencodings.h>
+#include <util/system.h>
+#include <util/strencodings.h>
 
 #include <boost/bind.hpp>
 #include <boost/signals2/signal.hpp>
diff --git a/src/rpc/util.cpp b/src/rpc/util.cpp
index c3f52742c19d..02e251d408ad 100644
--- a/src/rpc/util.cpp
+++ b/src/rpc/util.cpp
@@ -8,7 +8,7 @@
 #include <rpc/protocol.h>
 #include <rpc/util.h>
 #include <tinyformat.h>
-#include <utilstrencodings.h>
+#include <util/strencodings.h>
 
 // Converts a hex string to a public key if possible
 CPubKey HexToPubKey(const std::string& hex_in)
diff --git a/src/rpc/util.h b/src/rpc/util.h
index 5380d45a8356..6432d69d345c 100644
--- a/src/rpc/util.h
+++ b/src/rpc/util.h
@@ -8,7 +8,7 @@
 #include <pubkey.h>
 #include <script/standard.h>
 #include <univalue.h>
-#include <utilstrencodings.h>
+#include <util/strencodings.h>
 
 #include <boost/variant/static_visitor.hpp>
 
diff --git a/src/saltedhasher.h b/src/saltedhasher.h
index 00303a926072..b5ff2df62d10 100644
--- a/src/saltedhasher.h
+++ b/src/saltedhasher.h
@@ -7,6 +7,7 @@
 
 #include <hash.h>
 #include <uint256.h>
+#include <crypto/siphash.h>
 
 /** Helper classes for std::unordered_map and std::unordered_set hashing */
 
diff --git a/src/script/script.cpp b/src/script/script.cpp
index c8699e6a9d0e..f83a5c9e27a2 100644
--- a/src/script/script.cpp
+++ b/src/script/script.cpp
@@ -5,7 +5,7 @@
 
 #include <script/script.h>
 #include <tinyformat.h>
-#include <utilstrencodings.h>
+#include <util/strencodings.h>
 
 const char* GetOpName(opcodetype opcode)
 {
diff --git a/src/script/sigcache.cpp b/src/script/sigcache.cpp
index dddcd02af899..fa0bb9c6a297 100644
--- a/src/script/sigcache.cpp
+++ b/src/script/sigcache.cpp
@@ -9,7 +9,7 @@
 #include <pubkey.h>
 #include <random.h>
 #include <uint256.h>
-#include <util.h>
+#include <util/system.h>
 
 #include <cuckoocache.h>
 #include <boost/thread.hpp>
diff --git a/src/script/standard.cpp b/src/script/standard.cpp
index 90265811d758..07c1a10bb6ae 100644
--- a/src/script/standard.cpp
+++ b/src/script/standard.cpp
@@ -7,8 +7,8 @@
 
 #include <pubkey.h>
 #include <script/script.h>
-#include <util.h>
-#include <utilstrencodings.h>
+#include <util/system.h>
+#include <util/strencodings.h>
 
 
 typedef std::vector<unsigned char> valtype;
diff --git a/src/spork.h b/src/spork.h
index b7d92c3f9e21..cf7b5f852c31 100644
--- a/src/spork.h
+++ b/src/spork.h
@@ -7,7 +7,7 @@
 
 #include <hash.h>
 #include <net.h>
-#include <utilstrencodings.h>
+#include <util/strencodings.h>
 #include <key.h>
 
 #include <unordered_map>
diff --git a/src/stacktraces.cpp b/src/stacktraces.cpp
index ab1abde3824f..98697a6d6e4a 100644
--- a/src/stacktraces.cpp
+++ b/src/stacktraces.cpp
@@ -11,7 +11,7 @@
 #include <logging.h>
 #include <streams.h>
 #include <threadsafety.h>
-#include <utilstrencodings.h>
+#include <util/strencodings.h>
 
 #include <map>
 #include <vector>
diff --git a/src/statsd_client.cpp b/src/statsd_client.cpp
index 58997fb229c9..18a36361cab6 100644
--- a/src/statsd_client.cpp
+++ b/src/statsd_client.cpp
@@ -33,7 +33,7 @@ OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 #include <compat.h>
 #include <netbase.h>
 #include <random.h>
-#include <util.h>
+#include <util/system.h>
 
 #include <cmath>
 #include <cstdio>
diff --git a/src/sync.cpp b/src/sync.cpp
index 9f2576ffdca3..0658f9a4b904 100644
--- a/src/sync.cpp
+++ b/src/sync.cpp
@@ -6,8 +6,8 @@
 #include <tinyformat.h>
 
 #include <logging.h>
-#include <utilstrencodings.h>
-#include <utilthreadnames.h>
+#include <util/strencodings.h>
+#include <util/threadnames.h>
 
 #include <stdio.h>
 
diff --git a/src/sync.h b/src/sync.h
index 1c742ef21409..6572e7e70a73 100644
--- a/src/sync.h
+++ b/src/sync.h
@@ -7,6 +7,7 @@
 #define BITCOIN_SYNC_H
 
 #include <threadsafety.h>
+#include <util/macros.h>
 
 #include <condition_variable>
 #include <thread>
@@ -183,9 +184,6 @@ class SCOPED_LOCKABLE UniqueLock : public Base
 template<typename MutexArg>
 using DebugLock = UniqueLock<typename std::remove_reference<typename std::remove_pointer<MutexArg>::type>::type>;
 
-#define PASTE(x, y) x ## y
-#define PASTE2(x, y) PASTE(x, y)
-
 #define LOCK(cs) DebugLock<decltype(cs)> PASTE2(criticalblock, __COUNTER__)(cs, #cs, __FILE__, __LINE__)
 #define LOCK2(cs1, cs2)                                               \
     DebugLock<decltype(cs1)> criticalblock1(cs1, #cs1, __FILE__, __LINE__); \
diff --git a/src/test/addrman_tests.cpp b/src/test/addrman_tests.cpp
index 0f62b4a467b8..d43329121040 100644
--- a/src/test/addrman_tests.cpp
+++ b/src/test/addrman_tests.cpp
@@ -5,7 +5,7 @@
 #include <test/test_dash.h>
 #include <string>
 #include <boost/test/unit_test.hpp>
-#include <utilasmap.h>
+#include <util/asmap.h>
 #include <test/data/asmap.raw.h>
 
 #include <hash.h>
diff --git a/src/test/allocator_tests.cpp b/src/test/allocator_tests.cpp
index 2ff8677c1665..01489cd88bb1 100644
--- a/src/test/allocator_tests.cpp
+++ b/src/test/allocator_tests.cpp
@@ -2,7 +2,7 @@
 // Distributed under the MIT software license, see the accompanying
 // file COPYING or http://www.opensource.org/licenses/mit-license.php.
 
-#include <util.h>
+#include <util/system.h>
 
 #include <support/allocators/secure.h>
 #include <test/test_dash.h>
diff --git a/src/test/base32_tests.cpp b/src/test/base32_tests.cpp
index 8c21a5b6fc19..38dc17b62976 100644
--- a/src/test/base32_tests.cpp
+++ b/src/test/base32_tests.cpp
@@ -2,7 +2,7 @@
 // Distributed under the MIT software license, see the accompanying
 // file COPYING or http://www.opensource.org/licenses/mit-license.php.
 
-#include <utilstrencodings.h>
+#include <util/strencodings.h>
 #include <test/test_dash.h>
 
 #include <boost/test/unit_test.hpp>
diff --git a/src/test/base58_tests.cpp b/src/test/base58_tests.cpp
index 04cde66219fc..0154bb5c95e8 100644
--- a/src/test/base58_tests.cpp
+++ b/src/test/base58_tests.cpp
@@ -6,7 +6,7 @@
 
 #include <base58.h>
 #include <test/test_dash.h>
-#include <utilstrencodings.h>
+#include <util/strencodings.h>
 
 #include <univalue.h>
 
diff --git a/src/test/base64_tests.cpp b/src/test/base64_tests.cpp
index 084886809f7b..7888310ed073 100644
--- a/src/test/base64_tests.cpp
+++ b/src/test/base64_tests.cpp
@@ -2,7 +2,7 @@
 // Distributed under the MIT software license, see the accompanying
 // file COPYING or http://www.opensource.org/licenses/mit-license.php.
 
-#include <utilstrencodings.h>
+#include <util/strencodings.h>
 #include <test/test_dash.h>
 
 #include <boost/test/unit_test.hpp>
diff --git a/src/test/bip32_tests.cpp b/src/test/bip32_tests.cpp
index 1968879d1e1c..bd15854d12f6 100644
--- a/src/test/bip32_tests.cpp
+++ b/src/test/bip32_tests.cpp
@@ -7,8 +7,8 @@
 #include <key.h>
 #include <key_io.h>
 #include <uint256.h>
-#include <util.h>
-#include <utilstrencodings.h>
+#include <util/system.h>
+#include <util/strencodings.h>
 #include <test/test_dash.h>
 
 #include <string>
diff --git a/src/test/bip39_tests.cpp b/src/test/bip39_tests.cpp
index d7896e52e6b7..e5ffc6242fe4 100644
--- a/src/test/bip39_tests.cpp
+++ b/src/test/bip39_tests.cpp
@@ -6,8 +6,8 @@
 
 #include <key.h>
 #include <key_io.h>
-#include <util.h>
-#include <utilstrencodings.h>
+#include <util/system.h>
+#include <util/strencodings.h>
 #include <test/test_dash.h>
 #include <bip39.h>
 
diff --git a/src/test/blockfilter_tests.cpp b/src/test/blockfilter_tests.cpp
index de9f8f7c7825..6f93bc76e27c 100644
--- a/src/test/blockfilter_tests.cpp
+++ b/src/test/blockfilter_tests.cpp
@@ -10,7 +10,7 @@
 #include <serialize.h>
 #include <streams.h>
 #include <univalue.h>
-#include <utilstrencodings.h>
+#include <util/strencodings.h>
 
 #include <boost/test/unit_test.hpp>
 
diff --git a/src/test/bloom_tests.cpp b/src/test/bloom_tests.cpp
index e22e58daaaee..221127c8c6c6 100644
--- a/src/test/bloom_tests.cpp
+++ b/src/test/bloom_tests.cpp
@@ -13,8 +13,8 @@
 #include <serialize.h>
 #include <streams.h>
 #include <uint256.h>
-#include <util.h>
-#include <utilstrencodings.h>
+#include <util/system.h>
+#include <util/strencodings.h>
 #include <test/test_dash.h>
 
 #include <vector>
diff --git a/src/test/checkqueue_tests.cpp b/src/test/checkqueue_tests.cpp
index 444b6927bb5b..830fa95783a2 100644
--- a/src/test/checkqueue_tests.cpp
+++ b/src/test/checkqueue_tests.cpp
@@ -3,8 +3,8 @@
 // file COPYING or http://www.opensource.org/licenses/mit-license.php.
 
 #include <sync.h>
-#include <util.h>
-#include <utiltime.h>
+#include <util/system.h>
+#include <util/time.h>
 
 #include <test/test_dash.h>
 #include <checkqueue.h>
diff --git a/src/test/coins_tests.cpp b/src/test/coins_tests.cpp
index 2116b261c1b1..7ded9d4fabf7 100644
--- a/src/test/coins_tests.cpp
+++ b/src/test/coins_tests.cpp
@@ -6,7 +6,7 @@
 #include <script/standard.h>
 #include <uint256.h>
 #include <undo.h>
-#include <utilstrencodings.h>
+#include <util/strencodings.h>
 #include <test/test_dash.h>
 #include <validation.h>
 #include <consensus/validation.h>
diff --git a/src/test/compress_tests.cpp b/src/test/compress_tests.cpp
index 8521ff0b0ab1..03138eefab5f 100644
--- a/src/test/compress_tests.cpp
+++ b/src/test/compress_tests.cpp
@@ -3,7 +3,7 @@
 // file COPYING or http://www.opensource.org/licenses/mit-license.php.
 
 #include <compressor.h>
-#include <util.h>
+#include <util/system.h>
 #include <test/test_dash.h>
 
 #include <stdint.h>
diff --git a/src/test/crypto_tests.cpp b/src/test/crypto_tests.cpp
index 3a3c0c008f77..8350226ce8f6 100644
--- a/src/test/crypto_tests.cpp
+++ b/src/test/crypto_tests.cpp
@@ -14,7 +14,7 @@
 #include <crypto/hmac_sha256.h>
 #include <crypto/hmac_sha512.h>
 #include <random.h>
-#include <utilstrencodings.h>
+#include <util/strencodings.h>
 #include <test/test_dash.h>
 
 #include <vector>
diff --git a/src/test/denialofservice_tests.cpp b/src/test/denialofservice_tests.cpp
index 26e786ab7977..6f59c4ced2c7 100644
--- a/src/test/denialofservice_tests.cpp
+++ b/src/test/denialofservice_tests.cpp
@@ -11,7 +11,7 @@
 #include <pow.h>
 #include <script/sign.h>
 #include <serialize.h>
-#include <util.h>
+#include <util/system.h>
 #include <validation.h>
 
 #include <test/test_dash.h>
diff --git a/src/test/getarg_tests.cpp b/src/test/getarg_tests.cpp
index 3912be7d20ed..eec164c50083 100644
--- a/src/test/getarg_tests.cpp
+++ b/src/test/getarg_tests.cpp
@@ -2,7 +2,7 @@
 // Distributed under the MIT software license, see the accompanying
 // file COPYING or http://www.opensource.org/licenses/mit-license.php.
 
-#include <util.h>
+#include <util/system.h>
 #include <test/test_dash.h>
 
 #include <string>
diff --git a/src/test/governance_validators_tests.cpp b/src/test/governance_validators_tests.cpp
index dbefc1d97c80..68bbde20e3ce 100644
--- a/src/test/governance_validators_tests.cpp
+++ b/src/test/governance_validators_tests.cpp
@@ -1,7 +1,7 @@
 // Copyright (c) 2014-2020 The Dash Core developers
 
 #include <governance/governance-validators.h>
-#include <utilstrencodings.h>
+#include <util/strencodings.h>
 
 #include <test/data/proposals_valid.json.h>
 #include <test/data/proposals_invalid.json.h>
diff --git a/src/test/hash_tests.cpp b/src/test/hash_tests.cpp
index 5821834e3af4..8ee8f0012a8f 100644
--- a/src/test/hash_tests.cpp
+++ b/src/test/hash_tests.cpp
@@ -2,8 +2,9 @@
 // Distributed under the MIT software license, see the accompanying
 // file COPYING or http://www.opensource.org/licenses/mit-license.php.
 
+#include <crypto/siphash.h>
 #include <hash.h>
-#include <utilstrencodings.h>
+#include <util/strencodings.h>
 #include <test/test_dash.h>
 
 #include <vector>
diff --git a/src/test/key_io_tests.cpp b/src/test/key_io_tests.cpp
index 4cfe3d2e45b2..da6177a4e07a 100644
--- a/src/test/key_io_tests.cpp
+++ b/src/test/key_io_tests.cpp
@@ -8,7 +8,7 @@
 #include <key.h>
 #include <key_io.h>
 #include <script/script.h>
-#include <utilstrencodings.h>
+#include <util/strencodings.h>
 #include <test/test_dash.h>
 
 #include <boost/test/unit_test.hpp>
diff --git a/src/test/key_tests.cpp b/src/test/key_tests.cpp
index 157529b88047..564e25d03ce8 100644
--- a/src/test/key_tests.cpp
+++ b/src/test/key_tests.cpp
@@ -7,8 +7,8 @@
 #include <key_io.h>
 #include <script/script.h>
 #include <uint256.h>
-#include <util.h>
-#include <utilstrencodings.h>
+#include <util/system.h>
+#include <util/strencodings.h>
 #include <test/test_dash.h>
 
 #include <string>
diff --git a/src/test/mempool_tests.cpp b/src/test/mempool_tests.cpp
index 1631e2416620..e927de17ae8d 100644
--- a/src/test/mempool_tests.cpp
+++ b/src/test/mempool_tests.cpp
@@ -3,7 +3,7 @@
 // file COPYING or http://www.opensource.org/licenses/mit-license.php.
 
 #include <txmempool.h>
-#include <util.h>
+#include <util/system.h>
 
 #include <test/test_dash.h>
 
diff --git a/src/test/miner_tests.cpp b/src/test/miner_tests.cpp
index 11652ce669b3..7fe71e31e8bf 100644
--- a/src/test/miner_tests.cpp
+++ b/src/test/miner_tests.cpp
@@ -17,8 +17,8 @@
 #include <script/standard.h>
 #include <txmempool.h>
 #include <uint256.h>
-#include <util.h>
-#include <utilstrencodings.h>
+#include <util/system.h>
+#include <util/strencodings.h>
 
 #include <test/test_dash.h>
 
diff --git a/src/test/net_tests.cpp b/src/test/net_tests.cpp
index adc492be56fe..a4aa19ebb266 100644
--- a/src/test/net_tests.cpp
+++ b/src/test/net_tests.cpp
@@ -12,8 +12,8 @@
 #include <net.h>
 #include <netbase.h>
 #include <chainparams.h>
-#include <util.h>
-#include <utilstrencodings.h>
+#include <util/system.h>
+#include <util/strencodings.h>
 #include <version.h>
 
 #include <ios>
diff --git a/src/test/netbase_tests.cpp b/src/test/netbase_tests.cpp
index 25351d59dd1a..5da634182c30 100644
--- a/src/test/netbase_tests.cpp
+++ b/src/test/netbase_tests.cpp
@@ -8,7 +8,7 @@
 #include <serialize.h>
 #include <streams.h>
 #include <test/test_dash.h>
-#include <utilstrencodings.h>
+#include <util/strencodings.h>
 #include <version.h>
 
 #include <string>
diff --git a/src/test/policyestimator_tests.cpp b/src/test/policyestimator_tests.cpp
index 8604163ce6bb..67cb75c94176 100644
--- a/src/test/policyestimator_tests.cpp
+++ b/src/test/policyestimator_tests.cpp
@@ -5,7 +5,7 @@
 #include <policy/fees.h>
 #include <txmempool.h>
 #include <uint256.h>
-#include <util.h>
+#include <util/system.h>
 
 #include <test/test_dash.h>
 
diff --git a/src/test/pow_tests.cpp b/src/test/pow_tests.cpp
index dac389002439..fcccd8854b4c 100644
--- a/src/test/pow_tests.cpp
+++ b/src/test/pow_tests.cpp
@@ -6,7 +6,7 @@
 #include <chainparams.h>
 #include <pow.h>
 #include <random.h>
-#include <util.h>
+#include <util/system.h>
 #include <test/test_dash.h>
 
 #include <boost/test/unit_test.hpp>
diff --git a/src/test/script_tests.cpp b/src/test/script_tests.cpp
index 4c9d5762c70c..508dbf3770b1 100644
--- a/src/test/script_tests.cpp
+++ b/src/test/script_tests.cpp
@@ -10,8 +10,8 @@
 #include <script/script.h>
 #include <script/script_error.h>
 #include <script/sign.h>
-#include <util.h>
-#include <utilstrencodings.h>
+#include <util/system.h>
+#include <util/strencodings.h>
 #include <test/test_dash.h>
 
 #if defined(HAVE_CONSENSUS_LIB)
diff --git a/src/test/sighash_tests.cpp b/src/test/sighash_tests.cpp
index 99a4faf38b6b..1a1fba14cac0 100644
--- a/src/test/sighash_tests.cpp
+++ b/src/test/sighash_tests.cpp
@@ -11,8 +11,8 @@
 #include <serialize.h>
 #include <streams.h>
 #include <test/test_dash.h>
-#include <util.h>
-#include <utilstrencodings.h>
+#include <util/system.h>
+#include <util/strencodings.h>
 #include <version.h>
 
 #include <iostream>
diff --git a/src/test/skiplist_tests.cpp b/src/test/skiplist_tests.cpp
index 2adb8e5684c5..181eab518105 100644
--- a/src/test/skiplist_tests.cpp
+++ b/src/test/skiplist_tests.cpp
@@ -3,7 +3,7 @@
 // file COPYING or http://www.opensource.org/licenses/mit-license.php.
 
 #include <chain.h>
-#include <util.h>
+#include <util/system.h>
 #include <test/test_dash.h>
 
 #include <vector>
diff --git a/src/test/test_dash.cpp b/src/test/test_dash.cpp
index ab33c6360e32..9c170ce7d2f0 100644
--- a/src/test/test_dash.cpp
+++ b/src/test/test_dash.cpp
@@ -18,6 +18,7 @@
 #include <rpc/server.h>
 #include <rpc/register.h>
 #include <script/sigcache.h>
+#include <util/validation.h>
 
 #include <coinjoin/coinjoin.h>
 #include <evo/specialtx.h>
diff --git a/src/test/transaction_tests.cpp b/src/test/transaction_tests.cpp
index 7be50fbc5e4d..51e35a99cf1d 100644
--- a/src/test/transaction_tests.cpp
+++ b/src/test/transaction_tests.cpp
@@ -17,7 +17,7 @@
 #include <policy/policy.h>
 #include <script/script.h>
 #include <script/script_error.h>
-#include <utilstrencodings.h>
+#include <util/strencodings.h>
 
 #include <map>
 #include <string>
diff --git a/src/test/txindex_tests.cpp b/src/test/txindex_tests.cpp
index a46e59d447cb..aec776e90467 100644
--- a/src/test/txindex_tests.cpp
+++ b/src/test/txindex_tests.cpp
@@ -5,8 +5,8 @@
 #include <index/txindex.h>
 #include <script/standard.h>
 #include <test/test_dash.h>
-#include <util.h>
-#include <utiltime.h>
+#include <util/system.h>
+#include <util/time.h>
 #include <validation.h>
 
 #include <boost/test/unit_test.hpp>
diff --git a/src/test/txvalidationcache_tests.cpp b/src/test/txvalidationcache_tests.cpp
index b1969be95900..6b1f115787ca 100644
--- a/src/test/txvalidationcache_tests.cpp
+++ b/src/test/txvalidationcache_tests.cpp
@@ -12,7 +12,7 @@
 #include <script/standard.h>
 #include <script/sign.h>
 #include <test/test_dash.h>
-#include <utiltime.h>
+#include <util/time.h>
 #include <core_io.h>
 #include <keystore.h>
 #include <policy/policy.h>
diff --git a/src/test/util_tests.cpp b/src/test/util_tests.cpp
index 57475c5fa13b..65eb7f82b355 100644
--- a/src/test/util_tests.cpp
+++ b/src/test/util_tests.cpp
@@ -2,15 +2,16 @@
 // Distributed under the MIT software license, see the accompanying
 // file COPYING or http://www.opensource.org/licenses/mit-license.php.
 
-#include <util.h>
+#include <util/system.h>
 
 #include <clientversion.h>
 #include <primitives/transaction.h>
 #include <sync.h>
-#include <utilstrencodings.h>
-#include <utilstring.h>
-#include <utilmoneystr.h>
+#include <util/strencodings.h>
+#include <util/string.h>
+#include <util/moneystr.h>
 #include <test/test_dash.h>
+#include <util/vector.h>
 
 #include <stdint.h>
 #include <vector>
@@ -1162,4 +1163,109 @@ BOOST_AUTO_TEST_CASE(test_DirIsWritable)
     fs::remove(tmpdirname);
 }
 
+namespace {
+
+struct Tracker
+{
+    //! Points to the original object (possibly itself) we moved/copied from
+    const Tracker* origin;
+    //! How many copies where involved between the original object and this one (moves are not counted)
+    int copies;
+
+    Tracker() noexcept : origin(this), copies(0) {}
+    Tracker(const Tracker& t) noexcept : origin(t.origin), copies(t.copies + 1) {}
+    Tracker(Tracker&& t) noexcept : origin(t.origin), copies(t.copies) {}
+    Tracker& operator=(const Tracker& t) noexcept
+    {
+        origin = t.origin;
+        copies = t.copies + 1;
+        return *this;
+    }
+    Tracker& operator=(Tracker&& t) noexcept
+    {
+        origin = t.origin;
+        copies = t.copies;
+        return *this;
+    }
+};
+
+}
+
+BOOST_AUTO_TEST_CASE(test_tracked_vector)
+{
+    Tracker t1;
+    Tracker t2;
+    Tracker t3;
+
+    BOOST_CHECK(t1.origin == &t1);
+    BOOST_CHECK(t2.origin == &t2);
+    BOOST_CHECK(t3.origin == &t3);
+
+    auto v1 = Vector(t1);
+    BOOST_CHECK_EQUAL(v1.size(), 1);
+    BOOST_CHECK(v1[0].origin == &t1);
+    BOOST_CHECK_EQUAL(v1[0].copies, 1);
+
+    auto v2 = Vector(std::move(t2));
+    BOOST_CHECK_EQUAL(v2.size(), 1);
+    BOOST_CHECK(v2[0].origin == &t2);
+    BOOST_CHECK_EQUAL(v2[0].copies, 0);
+
+    auto v3 = Vector(t1, std::move(t2));
+    BOOST_CHECK_EQUAL(v3.size(), 2);
+    BOOST_CHECK(v3[0].origin == &t1);
+    BOOST_CHECK(v3[1].origin == &t2);
+    BOOST_CHECK_EQUAL(v3[0].copies, 1);
+    BOOST_CHECK_EQUAL(v3[1].copies, 0);
+
+    auto v4 = Vector(std::move(v3[0]), v3[1], std::move(t3));
+    BOOST_CHECK_EQUAL(v4.size(), 3);
+    BOOST_CHECK(v4[0].origin == &t1);
+    BOOST_CHECK(v4[1].origin == &t2);
+    BOOST_CHECK(v4[2].origin == &t3);
+    BOOST_CHECK_EQUAL(v4[0].copies, 1);
+    BOOST_CHECK_EQUAL(v4[1].copies, 1);
+    BOOST_CHECK_EQUAL(v4[2].copies, 0);
+
+    auto v5 = Cat(v1, v4);
+    BOOST_CHECK_EQUAL(v5.size(), 4);
+    BOOST_CHECK(v5[0].origin == &t1);
+    BOOST_CHECK(v5[1].origin == &t1);
+    BOOST_CHECK(v5[2].origin == &t2);
+    BOOST_CHECK(v5[3].origin == &t3);
+    BOOST_CHECK_EQUAL(v5[0].copies, 2);
+    BOOST_CHECK_EQUAL(v5[1].copies, 2);
+    BOOST_CHECK_EQUAL(v5[2].copies, 2);
+    BOOST_CHECK_EQUAL(v5[3].copies, 1);
+
+    auto v6 = Cat(std::move(v1), v3);
+    BOOST_CHECK_EQUAL(v6.size(), 3);
+    BOOST_CHECK(v6[0].origin == &t1);
+    BOOST_CHECK(v6[1].origin == &t1);
+    BOOST_CHECK(v6[2].origin == &t2);
+    BOOST_CHECK_EQUAL(v6[0].copies, 1);
+    BOOST_CHECK_EQUAL(v6[1].copies, 2);
+    BOOST_CHECK_EQUAL(v6[2].copies, 1);
+
+    auto v7 = Cat(v2, std::move(v4));
+    BOOST_CHECK_EQUAL(v7.size(), 4);
+    BOOST_CHECK(v7[0].origin == &t2);
+    BOOST_CHECK(v7[1].origin == &t1);
+    BOOST_CHECK(v7[2].origin == &t2);
+    BOOST_CHECK(v7[3].origin == &t3);
+    BOOST_CHECK_EQUAL(v7[0].copies, 1);
+    BOOST_CHECK_EQUAL(v7[1].copies, 1);
+    BOOST_CHECK_EQUAL(v7[2].copies, 1);
+    BOOST_CHECK_EQUAL(v7[3].copies, 0);
+
+    auto v8 = Cat(std::move(v2), std::move(v3));
+    BOOST_CHECK_EQUAL(v8.size(), 3);
+    BOOST_CHECK(v8[0].origin == &t2);
+    BOOST_CHECK(v8[1].origin == &t1);
+    BOOST_CHECK(v8[2].origin == &t2);
+    BOOST_CHECK_EQUAL(v8[0].copies, 0);
+    BOOST_CHECK_EQUAL(v8[1].copies, 1);
+    BOOST_CHECK_EQUAL(v8[2].copies, 0);
+}
+
 BOOST_AUTO_TEST_SUITE_END()
diff --git a/src/test/util_threadnames_tests.cpp b/src/test/util_threadnames_tests.cpp
index ecedf0b52ef0..23f0b75473af 100644
--- a/src/test/util_threadnames_tests.cpp
+++ b/src/test/util_threadnames_tests.cpp
@@ -2,7 +2,7 @@
 // Distributed under the MIT software license, see the accompanying
 // file COPYING or http://www.opensource.org/licenses/mit-license.php.
 
-#include <utilthreadnames.h>
+#include <util/threadnames.h>
 #include <test/test_dash.h>
 
 #include <thread>
diff --git a/src/timedata.cpp b/src/timedata.cpp
index f3c38b72276a..fd03c05bd5e3 100644
--- a/src/timedata.cpp
+++ b/src/timedata.cpp
@@ -11,8 +11,8 @@
 #include <netaddress.h>
 #include <sync.h>
 #include <ui_interface.h>
-#include <util.h>
-#include <utilstrencodings.h>
+#include <util/system.h>
+#include <util/strencodings.h>
 #include <warnings.h>
 
 
diff --git a/src/torcontrol.cpp b/src/torcontrol.cpp
index 1d98b8940e9c..e74ba8728fbc 100644
--- a/src/torcontrol.cpp
+++ b/src/torcontrol.cpp
@@ -5,10 +5,10 @@
 
 #include <chainparams.h>
 #include <torcontrol.h>
-#include <utilstrencodings.h>
+#include <util/strencodings.h>
 #include <netbase.h>
 #include <net.h>
-#include <util.h>
+#include <util/system.h>
 #include <crypto/hmac_sha256.h>
 
 #include <vector>
diff --git a/src/txdb.cpp b/src/txdb.cpp
index 2d7c709dac8c..d7b33093061b 100644
--- a/src/txdb.cpp
+++ b/src/txdb.cpp
@@ -10,9 +10,10 @@
 #include <random.h>
 #include <pow.h>
 #include <uint256.h>
-#include <util.h>
+#include <util/system.h>
 #include <ui_interface.h>
 #include <init.h>
+#include <util/vector.h>
 
 #include <stdint.h>
 
@@ -97,7 +98,7 @@ bool CCoinsViewDB::BatchWrite(CCoinsMap &mapCoins, const uint256 &hashBlock) {
     // A vector is used for future extensibility, as we may want to support
     // interrupting after partial writes from multiple independent reorgs.
     batch.Erase(DB_BEST_BLOCK);
-    batch.Write(DB_HEAD_BLOCKS, std::vector<uint256>{hashBlock, old_tip});
+    batch.Write(DB_HEAD_BLOCKS, Vector(hashBlock, old_tip));
 
     for (CCoinsMap::iterator it = mapCoins.begin(); it != mapCoins.end();) {
         if (it->second.flags & CCoinsCacheEntry::DIRTY) {
diff --git a/src/txmempool.cpp b/src/txmempool.cpp
index 4ff75e3b1dc8..c683a5135ab3 100644
--- a/src/txmempool.cpp
+++ b/src/txmempool.cpp
@@ -14,9 +14,9 @@
 #include <reverse_iterator.h>
 #include <streams.h>
 #include <timedata.h>
-#include <util.h>
-#include <utilmoneystr.h>
-#include <utiltime.h>
+#include <util/system.h>
+#include <util/moneystr.h>
+#include <util/time.h>
 #include <hash.h>
 
 #include <evo/specialtx.h>
diff --git a/src/txmempool.h b/src/txmempool.h
index c6c0883ffc85..bd428e9419b5 100644
--- a/src/txmempool.h
+++ b/src/txmempool.h
@@ -17,6 +17,7 @@
 #include <spentindex.h>
 #include <amount.h>
 #include <coins.h>
+#include <crypto/siphash.h>
 #include <indirectmap.h>
 #include <policy/feerate.h>
 #include <primitives/transaction.h>
diff --git a/src/ui_interface.cpp b/src/ui_interface.cpp
index c0f7defa4619..17565bc6c9bb 100644
--- a/src/ui_interface.cpp
+++ b/src/ui_interface.cpp
@@ -3,7 +3,7 @@
 // file COPYING or http://www.opensource.org/licenses/mit-license.php.
 
 #include <ui_interface.h>
-#include <util.h>
+#include <util/system.h>
 
 CClientUIInterface uiInterface;
 
@@ -17,13 +17,3 @@ void InitWarning(const std::string& str)
 {
     uiInterface.ThreadSafeMessageBox(str, "", CClientUIInterface::MSG_WARNING);
 }
-
-std::string AmountHighWarn(const std::string& optname)
-{
-    return strprintf(_("%s is set very high!"), optname);
-}
-
-std::string AmountErrMsg(const char* const optname, const std::string& strValue)
-{
-    return strprintf(_("Invalid amount for -%s=<amount>: '%s'"), optname, strValue);
-}
diff --git a/src/ui_interface.h b/src/ui_interface.h
index 21be5e9b1f7b..4452a9ed28f4 100644
--- a/src/ui_interface.h
+++ b/src/ui_interface.h
@@ -124,10 +124,6 @@ void InitWarning(const std::string& str);
 /** Show error message **/
 bool InitError(const std::string& str);
 
-std::string AmountHighWarn(const std::string& optname);
-
-std::string AmountErrMsg(const char* const optname, const std::string& strValue);
-
 extern CClientUIInterface uiInterface;
 
 #endif // BITCOIN_UI_INTERFACE_H
diff --git a/src/uint256.cpp b/src/uint256.cpp
index 9afda5c5a0af..dfd9218b86e6 100644
--- a/src/uint256.cpp
+++ b/src/uint256.cpp
@@ -5,7 +5,7 @@
 
 #include <uint256.h>
 
-#include <utilstrencodings.h>
+#include <util/strencodings.h>
 
 #include <stdio.h>
 #include <string.h>
diff --git a/src/undo.h b/src/undo.h
index 636f748867bc..91656ce904d3 100644
--- a/src/undo.h
+++ b/src/undo.h
@@ -11,6 +11,7 @@
 #include <consensus/consensus.h>
 #include <primitives/transaction.h>
 #include <serialize.h>
+#include <version.h>
 
 /** Formatter for undo information for a CTxIn
  *
diff --git a/src/utilasmap.cpp b/src/util/asmap.cpp
similarity index 100%
rename from src/utilasmap.cpp
rename to src/util/asmap.cpp
diff --git a/src/utilasmap.h b/src/util/asmap.h
similarity index 75%
rename from src/utilasmap.h
rename to src/util/asmap.h
index 2840f2806948..a0e14013c56a 100644
--- a/src/utilasmap.h
+++ b/src/util/asmap.h
@@ -2,9 +2,9 @@
 // Distributed under the MIT software license, see the accompanying
 // file COPYING or http://www.opensource.org/licenses/mit-license.php.
 
-#ifndef BITCOIN_UTILASMAP_H
-#define BITCOIN_UTILASMAP_H
+#ifndef BITCOIN_UTIL_ASMAP_H
+#define BITCOIN_UTIL_ASMAP_H
 
 uint32_t Interpret(const std::vector<bool> &asmap, const std::vector<bool> &ip);
 
-#endif // BITCOIN_UTILASMAP_H
+#endif // BITCOIN_UTIL_ASMAP_H
diff --git a/src/util/bytevectorhash.cpp b/src/util/bytevectorhash.cpp
new file mode 100644
index 000000000000..f87d0e04b32f
--- /dev/null
+++ b/src/util/bytevectorhash.cpp
@@ -0,0 +1,18 @@
+// Copyright (c) 2018 The Bitcoin Core developers
+// Distributed under the MIT software license, see the accompanying
+// file COPYING or http://www.opensource.org/licenses/mit-license.php.
+
+#include <crypto/siphash.h>
+#include <random.h>
+#include <util/bytevectorhash.h>
+
+ByteVectorHash::ByteVectorHash()
+{
+    GetRandBytes(reinterpret_cast<unsigned char*>(&m_k0), sizeof(m_k0));
+    GetRandBytes(reinterpret_cast<unsigned char*>(&m_k1), sizeof(m_k1));
+}
+
+size_t ByteVectorHash::operator()(const std::vector<unsigned char>& input) const
+{
+    return CSipHasher(m_k0, m_k1).Write(input.data(), input.size()).Finalize();
+}
diff --git a/src/util/bytevectorhash.h b/src/util/bytevectorhash.h
new file mode 100644
index 000000000000..b88c17460b49
--- /dev/null
+++ b/src/util/bytevectorhash.h
@@ -0,0 +1,26 @@
+// Copyright (c) 2018 The Bitcoin Core developers
+// Distributed under the MIT software license, see the accompanying
+// file COPYING or http://www.opensource.org/licenses/mit-license.php.
+
+#ifndef BITCOIN_UTIL_BYTEVECTORHASH_H
+#define BITCOIN_UTIL_BYTEVECTORHASH_H
+
+#include <stdint.h>
+#include <vector>
+
+/**
+ * Implementation of Hash named requirement for types that internally store a byte array. This may
+ * be used as the hash function in std::unordered_set or std::unordered_map over such types.
+ * Internally, this uses a random instance of SipHash-2-4.
+ */
+class ByteVectorHash final
+{
+private:
+    uint64_t m_k0, m_k1;
+
+public:
+    ByteVectorHash();
+    size_t operator()(const std::vector<unsigned char>& input) const;
+};
+
+#endif // BITCOIN_UTIL_BYTEVECTORHASH_H
diff --git a/src/util/error.cpp b/src/util/error.cpp
new file mode 100644
index 000000000000..c29538fda1ad
--- /dev/null
+++ b/src/util/error.cpp
@@ -0,0 +1,17 @@
+// Copyright (c) 2010-2018 The Bitcoin Core developers
+// Distributed under the MIT software license, see the accompanying
+// file COPYING or http://www.opensource.org/licenses/mit-license.php.
+
+#include <util/error.h>
+
+#include <util/system.h>
+
+std::string AmountHighWarn(const std::string& optname)
+{
+    return strprintf(_("%s is set very high!"), optname);
+}
+
+std::string AmountErrMsg(const char* const optname, const std::string& strValue)
+{
+    return strprintf(_("Invalid amount for -%s=<amount>: '%s'"), optname, strValue);
+}
diff --git a/src/util/error.h b/src/util/error.h
new file mode 100644
index 000000000000..102c2a859351
--- /dev/null
+++ b/src/util/error.h
@@ -0,0 +1,23 @@
+// Copyright (c) 2010-2018 The Bitcoin Core developers
+// Distributed under the MIT software license, see the accompanying
+// file COPYING or http://www.opensource.org/licenses/mit-license.php.
+
+#ifndef BITCOIN_UTIL_ERROR_H
+#define BITCOIN_UTIL_ERROR_H
+
+/**
+ * util/error.h is a common place for definitions of simple error types and
+ * string functions. Types and functions defined here should not require any
+ * outside dependencies.
+ *
+ * Error types defined here can be used in different parts of the bitcoin
+ * codebase, to avoid the need to write boilerplate code catching and
+ * translating errors passed across wallet/node/rpc/gui code boundaries.
+ */
+
+#include <string>
+
+std::string AmountHighWarn(const std::string& optname);
+std::string AmountErrMsg(const char* const optname, const std::string& strValue);
+
+#endif // BITCOIN_UTIL_ERROR_H
diff --git a/src/util/fees.cpp b/src/util/fees.cpp
new file mode 100644
index 000000000000..5fdaa1284cd3
--- /dev/null
+++ b/src/util/fees.cpp
@@ -0,0 +1,42 @@
+// Copyright (c) 2009-2010 Satoshi Nakamoto
+// Copyright (c) 2009-2018 The Bitcoin Core developers
+// Distributed under the MIT software license, see the accompanying
+// file COPYING or http://www.opensource.org/licenses/mit-license.php.
+
+#include <policy/fees.h>
+
+#include <string>
+
+std::string StringForFeeReason(FeeReason reason) {
+    static const std::map<FeeReason, std::string> fee_reason_strings = {
+        {FeeReason::NONE, "None"},
+        {FeeReason::HALF_ESTIMATE, "Half Target 60% Threshold"},
+        {FeeReason::FULL_ESTIMATE, "Target 85% Threshold"},
+        {FeeReason::DOUBLE_ESTIMATE, "Double Target 95% Threshold"},
+        {FeeReason::CONSERVATIVE, "Conservative Double Target longer horizon"},
+        {FeeReason::MEMPOOL_MIN, "Mempool Min Fee"},
+        {FeeReason::PAYTXFEE, "PayTxFee set"},
+        {FeeReason::FALLBACK, "Fallback fee"},
+        {FeeReason::REQUIRED, "Minimum Required Fee"},
+        {FeeReason::MAXTXFEE, "MaxTxFee limit"}
+    };
+    auto reason_string = fee_reason_strings.find(reason);
+
+    if (reason_string == fee_reason_strings.end()) return "Unknown";
+
+    return reason_string->second;
+}
+
+bool FeeModeFromString(const std::string& mode_string, FeeEstimateMode& fee_estimate_mode) {
+    static const std::map<std::string, FeeEstimateMode> fee_modes = {
+        {"UNSET", FeeEstimateMode::UNSET},
+        {"ECONOMICAL", FeeEstimateMode::ECONOMICAL},
+        {"CONSERVATIVE", FeeEstimateMode::CONSERVATIVE},
+    };
+    auto mode = fee_modes.find(mode_string);
+
+    if (mode == fee_modes.end()) return false;
+
+    fee_estimate_mode = mode->second;
+    return true;
+}
diff --git a/src/util/fees.h b/src/util/fees.h
new file mode 100644
index 000000000000..fc355ce9c238
--- /dev/null
+++ b/src/util/fees.h
@@ -0,0 +1,16 @@
+// Copyright (c) 2009-2010 Satoshi Nakamoto
+// Copyright (c) 2009-2018 The Bitcoin Core developers
+// Distributed under the MIT software license, see the accompanying
+// file COPYING or http://www.opensource.org/licenses/mit-license.php.
+#ifndef BITCOIN_UTIL_FEES_H
+#define BITCOIN_UTIL_FEES_H
+
+#include <string>
+
+enum class FeeEstimateMode;
+enum class FeeReason;
+
+bool FeeModeFromString(const std::string& mode_string, FeeEstimateMode& fee_estimate_mode);
+std::string StringForFeeReason(FeeReason reason);
+
+#endif // BITCOIN_UTIL_FEES_H
diff --git a/src/util/macros.h b/src/util/macros.h
new file mode 100644
index 000000000000..36ea87c0fe7e
--- /dev/null
+++ b/src/util/macros.h
@@ -0,0 +1,11 @@
+// Copyright (c) 2019 The Bitcoin Core developers
+// Distributed under the MIT software license, see the accompanying
+// file COPYING or http://www.opensource.org/licenses/mit-license.php.
+
+#ifndef BITCOIN_UTIL_MACROS_H
+#define BITCOIN_UTIL_MACROS_H
+
+#define PASTE(x, y) x ## y
+#define PASTE2(x, y) PASTE(x, y)
+
+#endif // BITCOIN_UTIL_MACROS_H
diff --git a/src/utilmemory.h b/src/util/memory.h
similarity index 89%
rename from src/utilmemory.h
rename to src/util/memory.h
index e71fe922845e..15ecf8f80d4d 100644
--- a/src/utilmemory.h
+++ b/src/util/memory.h
@@ -3,8 +3,8 @@
 // Distributed under the MIT software license, see the accompanying
 // file COPYING or http://www.opensource.org/licenses/mit-license.php.
 
-#ifndef BITCOIN_UTILMEMORY_H
-#define BITCOIN_UTILMEMORY_H
+#ifndef BITCOIN_UTIL_MEMORY_H
+#define BITCOIN_UTIL_MEMORY_H
 
 #include <memory>
 #include <utility>
diff --git a/src/utilmoneystr.cpp b/src/util/moneystr.cpp
similarity index 97%
rename from src/utilmoneystr.cpp
rename to src/util/moneystr.cpp
index 656d7c51b73d..d434a0c8e011 100644
--- a/src/utilmoneystr.cpp
+++ b/src/util/moneystr.cpp
@@ -3,11 +3,11 @@
 // Distributed under the MIT software license, see the accompanying
 // file COPYING or http://www.opensource.org/licenses/mit-license.php.
 
-#include <utilmoneystr.h>
+#include <util/moneystr.h>
 
 #include <primitives/transaction.h>
 #include <tinyformat.h>
-#include <utilstrencodings.h>
+#include <util/strencodings.h>
 
 std::string FormatMoney(const CAmount& n)
 {
diff --git a/src/utilmoneystr.h b/src/util/moneystr.h
similarity index 70%
rename from src/utilmoneystr.h
rename to src/util/moneystr.h
index 895f6f052044..ee78217baaed 100644
--- a/src/utilmoneystr.h
+++ b/src/util/moneystr.h
@@ -6,8 +6,8 @@
 /**
  * Money parsing/formatting utilities.
  */
-#ifndef BITCOIN_UTILMONEYSTR_H
-#define BITCOIN_UTILMONEYSTR_H
+#ifndef BITCOIN_UTIL_MONEYSTR_H
+#define BITCOIN_UTIL_MONEYSTR_H
 
 #include <amount.h>
 #include <attributes.h>
@@ -19,7 +19,7 @@
  * JSON but use AmountFromValue and ValueFromAmount for that.
  */
 std::string FormatMoney(const CAmount& n);
-NODISCARD bool ParseMoney(const std::string& str, CAmount& nRet);
-NODISCARD bool ParseMoney(const char* pszIn, CAmount& nRet);
+[[nodiscard]] bool ParseMoney(const std::string& str, CAmount& nRet);
+[[nodiscard]] bool ParseMoney(const char* pszIn, CAmount& nRet);
 
-#endif // BITCOIN_UTILMONEYSTR_H
+#endif // BITCOIN_UTIL_MONEYSTR_H
diff --git a/src/util/serfloat.cpp b/src/util/serfloat.cpp
new file mode 100644
index 000000000000..8edca924cd7b
--- /dev/null
+++ b/src/util/serfloat.cpp
@@ -0,0 +1,64 @@
+// Copyright (c) 2021 The Bitcoin Core developers
+// Distributed under the MIT software license, see the accompanying
+// file COPYING or http://www.opensource.org/licenses/mit-license.php.
+
+#include <util/serfloat.h>
+
+#include <cmath>
+#include <limits>
+
+double DecodeDouble(uint64_t v) noexcept {
+    static constexpr double NANVAL = std::numeric_limits<double>::quiet_NaN();
+    static constexpr double INFVAL = std::numeric_limits<double>::infinity();
+    double sign = 1.0;
+    if (v & 0x8000000000000000) {
+        sign = -1.0;
+        v ^= 0x8000000000000000;
+    }
+    // Zero
+    if (v == 0) return copysign(0.0, sign);
+    // Infinity
+    if (v == 0x7ff0000000000000) return copysign(INFVAL, sign);
+    // Other numbers
+    int exp = (v & 0x7FF0000000000000) >> 52;
+    uint64_t man = v & 0xFFFFFFFFFFFFF;
+    if (exp == 2047) {
+        // NaN
+        return NANVAL;
+    } else if (exp == 0) {
+        // Subnormal
+        return copysign(ldexp((double)man, -1074), sign);
+    } else {
+        // Normal
+        return copysign(ldexp((double)(man + 0x10000000000000), -1075 + exp), sign);
+    }
+}
+
+uint64_t EncodeDouble(double f) noexcept {
+    int cls = std::fpclassify(f);
+    uint64_t sign = 0;
+    if (copysign(1.0, f) == -1.0) {
+        f = -f;
+        sign = 0x8000000000000000;
+    }
+    // Zero
+    if (cls == FP_ZERO) return sign;
+    // Infinity
+    if (cls == FP_INFINITE) return sign | 0x7ff0000000000000;
+    // NaN
+    if (cls == FP_NAN) return 0x7ff8000000000000;
+    // Other numbers
+    int exp;
+    uint64_t man = std::round(std::frexp(f, &exp) * 9007199254740992.0);
+    if (exp < -1021) {
+        // Too small to represent, encode 0
+        if (exp < -1084) return sign;
+        // Subnormal numbers
+        return sign | (man >> (-1021 - exp));
+    } else {
+        // Too big to represent, encode infinity
+        if (exp > 1024) return sign | 0x7ff0000000000000;
+        // Normal numbers
+        return sign | (((uint64_t)(1022 + exp)) << 52) | (man & 0xFFFFFFFFFFFFF);
+    }
+}
diff --git a/src/util/serfloat.h b/src/util/serfloat.h
new file mode 100644
index 000000000000..4d912b0176e5
--- /dev/null
+++ b/src/util/serfloat.h
@@ -0,0 +1,16 @@
+// Copyright (c) 2021 The Bitcoin Core developers
+// Distributed under the MIT software license, see the accompanying
+// file COPYING or http://www.opensource.org/licenses/mit-license.php.
+
+#ifndef BITCOIN_UTIL_SERFLOAT_H
+#define BITCOIN_UTIL_SERFLOAT_H
+
+#include <stdint.h>
+
+/* Encode a double using the IEEE 754 binary64 format. All NaNs are encoded as x86/ARM's
+ * positive quiet NaN with payload 0. */
+uint64_t EncodeDouble(double f) noexcept;
+/* Reverse operation of DecodeDouble. DecodeDouble(EncodeDouble(f))==f unless isnan(f). */
+double DecodeDouble(uint64_t v) noexcept;
+
+#endif // BITCOIN_UTIL_SERFLOAT_H
diff --git a/src/utilstrencodings.cpp b/src/util/strencodings.cpp
similarity index 99%
rename from src/utilstrencodings.cpp
rename to src/util/strencodings.cpp
index 15dbbba5dae0..e1d24fe54a94 100644
--- a/src/utilstrencodings.cpp
+++ b/src/util/strencodings.cpp
@@ -3,8 +3,8 @@
 // Distributed under the MIT software license, see the accompanying
 // file COPYING or http://www.opensource.org/licenses/mit-license.php.
 
-#include <utilstrencodings.h>
-#include <utilstring.h>
+#include <util/strencodings.h>
+#include <util/string.h>
 
 #include <tinyformat.h>
 
@@ -266,7 +266,7 @@ std::string DecodeBase32(const std::string& str, bool* pf_invalid)
     return std::string((const char*)vchRet.data(), vchRet.size());
 }
 
-NODISCARD static bool ParsePrechecks(const std::string& str)
+[[nodiscard]] static bool ParsePrechecks(const std::string& str)
 {
     if (str.empty()) // No empty string allowed
         return false;
diff --git a/src/utilstrencodings.h b/src/util/strencodings.h
similarity index 91%
rename from src/utilstrencodings.h
rename to src/util/strencodings.h
index 2a55ccc05ad9..f683f245d100 100644
--- a/src/utilstrencodings.h
+++ b/src/util/strencodings.h
@@ -6,8 +6,8 @@
 /**
  * Utilities for converting data from/to strings.
  */
-#ifndef BITCOIN_UTILSTRENCODINGS_H
-#define BITCOIN_UTILSTRENCODINGS_H
+#ifndef BITCOIN_UTIL_STRENCODINGS_H
+#define BITCOIN_UTIL_STRENCODINGS_H
 
 #include <attributes.h>
 #include <span.h>
@@ -92,42 +92,42 @@ constexpr bool IsDigit(char c)
  * @returns true if the entire string could be parsed as valid integer,
  *   false if not the entire string could be parsed or when overflow or underflow occurred.
  */
-NODISCARD bool ParseInt32(const std::string& str, int32_t *out);
+[[nodiscard]] bool ParseInt32(const std::string& str, int32_t *out);
 
 /**
  * Convert string to signed 64-bit integer with strict parse error feedback.
  * @returns true if the entire string could be parsed as valid integer,
  *   false if not the entire string could be parsed or when overflow or underflow occurred.
  */
-NODISCARD bool ParseInt64(const std::string& str, int64_t *out);
+[[nodiscard]] bool ParseInt64(const std::string& str, int64_t *out);
 
 /**
  * Convert decimal string to unsigned 8-bit integer with strict parse error feedback.
  * @returns true if the entire string could be parsed as valid integer,
  *   false if not the entire string could be parsed or when overflow or underflow occurred.
  */
-NODISCARD bool ParseUInt8(const std::string& str, uint8_t *out);
+[[nodiscard]] bool ParseUInt8(const std::string& str, uint8_t *out);
 
 /**
  * Convert decimal string to unsigned 32-bit integer with strict parse error feedback.
  * @returns true if the entire string could be parsed as valid integer,
  *   false if not the entire string could be parsed or when overflow or underflow occurred.
  */
-NODISCARD bool ParseUInt32(const std::string& str, uint32_t *out);
+[[nodiscard]] bool ParseUInt32(const std::string& str, uint32_t *out);
 
 /**
  * Convert decimal string to unsigned 64-bit integer with strict parse error feedback.
  * @returns true if the entire string could be parsed as valid integer,
  *   false if not the entire string could be parsed or when overflow or underflow occurred.
  */
-NODISCARD bool ParseUInt64(const std::string& str, uint64_t *out);
+[[nodiscard]] bool ParseUInt64(const std::string& str, uint64_t *out);
 
 /**
  * Convert string to double with strict parse error feedback.
  * @returns true if the entire string could be parsed as valid double,
  *   false if not the entire string could be parsed or when overflow or underflow occurred.
  */
-NODISCARD bool ParseDouble(const std::string& str, double *out);
+[[nodiscard]] bool ParseDouble(const std::string& str, double *out);
 
 /**
  * Convert a span of bytes to a lower-case hexadecimal string.
@@ -161,7 +161,7 @@ bool TimingResistantEqual(const T& a, const T& b)
  * @returns true on success, false on error.
  * @note The result must be in the range (-10^18,10^18), otherwise an overflow error will trigger.
  */
-NODISCARD bool ParseFixedPoint(const std::string &val, int decimals, int64_t *amount_out);
+[[nodiscard]] bool ParseFixedPoint(const std::string &val, int decimals, int64_t *amount_out);
 
 /** Convert from one power-of-2 number base to another. */
 template<int frombits, int tobits, bool pad, typename O, typename I>
@@ -187,4 +187,4 @@ bool ConvertBits(const O& outfn, I it, I end) {
     return true;
 }
 
-#endif // BITCOIN_UTILSTRENCODINGS_H
+#endif // BITCOIN_UTIL_STRENCODINGS_H
diff --git a/src/utilstring.cpp b/src/util/string.cpp
similarity index 88%
rename from src/utilstring.cpp
rename to src/util/string.cpp
index 28b95ff75b42..8ea3a1afc6a0 100644
--- a/src/utilstring.cpp
+++ b/src/util/string.cpp
@@ -2,4 +2,4 @@
 // Distributed under the MIT software license, see the accompanying
 // file COPYING or http://www.opensource.org/licenses/mit-license.php.
 
-#include <utilstring.h>
+#include <util/string.h>
diff --git a/src/utilstring.h b/src/util/string.h
similarity index 85%
rename from src/utilstring.h
rename to src/util/string.h
index f969dc5afb3c..223216b4cc1b 100644
--- a/src/utilstring.h
+++ b/src/util/string.h
@@ -2,8 +2,8 @@
 // Distributed under the MIT software license, see the accompanying
 // file COPYING or http://www.opensource.org/licenses/mit-license.php.
 
-#ifndef BITCOIN_UTILSTRING_H
-#define BITCOIN_UTILSTRING_H
+#ifndef BITCOIN_UTIL_STRING_H
+#define BITCOIN_UTIL_STRING_H
 
 #include <attributes.h>
 
@@ -15,7 +15,7 @@
 #include <string>
 #include <vector>
 
-NODISCARD inline std::string TrimString(const std::string& str, const std::string& pattern = " \f\n\r\t\v")
+[[nodiscard]] inline std::string TrimString(const std::string& str, const std::string& pattern = " \f\n\r\t\v")
 {
     std::string::size_type front = str.find_first_not_of(pattern);
     if (front == std::string::npos) {
@@ -59,7 +59,7 @@ inline std::string Join(const std::vector<std::string>& list, const std::string&
 /**
  * Check if a string does not contain any embedded NUL (\0) characters
  */
-NODISCARD inline bool ValidAsCString(const std::string& str) noexcept
+[[nodiscard]] inline bool ValidAsCString(const std::string& str) noexcept
 {
     return str.size() == strlen(str.c_str());
 }
@@ -68,11 +68,11 @@ NODISCARD inline bool ValidAsCString(const std::string& str) noexcept
  * Check whether a container begins with the given prefix.
  */
 template <typename T1, size_t PREFIX_LEN>
-NODISCARD inline bool HasPrefix(const T1& obj,
+[[nodiscard]] inline bool HasPrefix(const T1& obj,
                                 const std::array<uint8_t, PREFIX_LEN>& prefix)
 {
     return obj.size() >= PREFIX_LEN &&
            std::equal(std::begin(prefix), std::end(prefix), std::begin(obj));
 }
 
-#endif // BITCOIN_UTILSTRING_H
+#endif // BITCOIN_UTIL_STRING_H
diff --git a/src/util.cpp b/src/util/system.cpp
similarity index 99%
rename from src/util.cpp
rename to src/util/system.cpp
index 0ac603e5ceee..75c90f9e97a4 100644
--- a/src/util.cpp
+++ b/src/util/system.cpp
@@ -4,7 +4,7 @@
 // Distributed under the MIT software license, see the accompanying
 // file COPYING or http://www.opensource.org/licenses/mit-license.php.
 
-#include <util.h>
+#include <util/system.h>
 
 #include <support/allocators/secure.h>
 #include <chainparamsbase.h>
@@ -12,7 +12,7 @@
 #include <random.h>
 #include <serialize.h>
 #include <stacktraces.h>
-#include <utilstrencodings.h>
+#include <util/strencodings.h>
 
 #include <stdarg.h>
 
diff --git a/src/util.h b/src/util/system.h
similarity index 98%
rename from src/util.h
rename to src/util/system.h
index 39fd7be5e85a..c864c350dad8 100644
--- a/src/util.h
+++ b/src/util/system.h
@@ -8,8 +8,8 @@
  * Server/client environment: argument handling, config file parsing,
  * thread wrappers, startup time
  */
-#ifndef BITCOIN_UTIL_H
-#define BITCOIN_UTIL_H
+#ifndef BITCOIN_UTIL_SYSTEM_H
+#define BITCOIN_UTIL_SYSTEM_H
 
 #if defined(HAVE_CONFIG_H)
 #include <config/dash-config.h>
@@ -20,10 +20,10 @@
 #include <fs.h>
 #include <logging.h>
 #include <sync.h>
-#include <utilthreadnames.h>
+#include <util/threadnames.h>
 #include <tinyformat.h>
-#include <utiltime.h>
-#include <utilmemory.h>
+#include <util/time.h>
+#include <util/memory.h>
 #include <amount.h>
 
 #include <atomic>
@@ -380,4 +380,4 @@ inline void insert(std::set<TsetT>& dst, const Tsrc& src) {
 
 } // namespace util
 
-#endif // BITCOIN_UTIL_H
+#endif // BITCOIN_UTIL_SYSTEM_H
diff --git a/src/utilthreadnames.cpp b/src/util/threadnames.cpp
similarity index 98%
rename from src/utilthreadnames.cpp
rename to src/util/threadnames.cpp
index 9fa8c17f1dc1..845508a94739 100644
--- a/src/utilthreadnames.cpp
+++ b/src/util/threadnames.cpp
@@ -9,7 +9,7 @@
 #include <atomic>
 #include <thread>
 
-#include <utilthreadnames.h>
+#include <util/threadnames.h>
 
 #ifdef HAVE_SYS_PRCTL_H
 #include <sys/prctl.h> // For prctl, PR_SET_NAME, PR_GET_NAME
diff --git a/src/utilthreadnames.h b/src/util/threadnames.h
similarity index 88%
rename from src/utilthreadnames.h
rename to src/util/threadnames.h
index 075c575a9ff7..aaf07b9bf873 100644
--- a/src/utilthreadnames.h
+++ b/src/util/threadnames.h
@@ -2,8 +2,8 @@
 // Distributed under the MIT software license, see the accompanying
 // file COPYING or http://www.opensource.org/licenses/mit-license.php.
 
-#ifndef BITCOIN_UTILTHREADNAMES_H
-#define BITCOIN_UTILTHREADNAMES_H
+#ifndef BITCOIN_UTIL_THREADNAMES_H
+#define BITCOIN_UTIL_THREADNAMES_H
 
 #include <string>
 
diff --git a/src/utiltime.cpp b/src/util/time.cpp
similarity index 99%
rename from src/utiltime.cpp
rename to src/util/time.cpp
index 5acd3ba394c3..edf6424ee361 100644
--- a/src/utiltime.cpp
+++ b/src/util/time.cpp
@@ -7,7 +7,7 @@
 #include <config/dash-config.h>
 #endif
 
-#include <utiltime.h>
+#include <util/time.h>
 
 #include <atomic>
 #include <boost/date_time/posix_time/posix_time.hpp>
diff --git a/src/utiltime.h b/src/util/time.h
similarity index 93%
rename from src/utiltime.h
rename to src/util/time.h
index e27b44e3ad4b..38361a141507 100644
--- a/src/utiltime.h
+++ b/src/util/time.h
@@ -3,8 +3,8 @@
 // Distributed under the MIT software license, see the accompanying
 // file COPYING or http://www.opensource.org/licenses/mit-license.php.
 
-#ifndef BITCOIN_UTILTIME_H
-#define BITCOIN_UTILTIME_H
+#ifndef BITCOIN_UTIL_TIME_H
+#define BITCOIN_UTIL_TIME_H
 
 #include <stdint.h>
 #include <string>
@@ -42,4 +42,4 @@ std::string FormatISO8601DateTime(int64_t nTime);
 std::string FormatISO8601Date(int64_t nTime);
 std::string FormatISO8601Time(int64_t nTime);
 
-#endif // BITCOIN_UTILTIME_H
+#endif // BITCOIN_UTIL_TIME_H
diff --git a/src/util/url.cpp b/src/util/url.cpp
new file mode 100644
index 000000000000..49eacbf2d019
--- /dev/null
+++ b/src/util/url.cpp
@@ -0,0 +1,21 @@
+// Copyright (c) 2015-2018 The Bitcoin Core developers
+// Distributed under the MIT software license, see the accompanying
+// file COPYING or http://www.opensource.org/licenses/mit-license.php.
+
+#include <util/url.h>
+
+#include <event2/http.h>
+#include <stdlib.h>
+#include <string>
+
+std::string urlDecode(const std::string &urlEncoded) {
+    std::string res;
+    if (!urlEncoded.empty()) {
+        char *decoded = evhttp_uridecode(urlEncoded.c_str(), false, nullptr);
+        if (decoded) {
+            res = std::string(decoded);
+            free(decoded);
+        }
+    }
+    return res;
+}
diff --git a/src/util/url.h b/src/util/url.h
new file mode 100644
index 000000000000..3d7315a33830
--- /dev/null
+++ b/src/util/url.h
@@ -0,0 +1,12 @@
+// Copyright (c) 2015-2018 The Bitcoin Core developers
+// Distributed under the MIT software license, see the accompanying
+// file COPYING or http://www.opensource.org/licenses/mit-license.php.
+
+#ifndef BITCOIN_UTIL_URL_H
+#define BITCOIN_UTIL_URL_H
+
+#include <string>
+
+std::string urlDecode(const std::string &urlEncoded);
+
+#endif // BITCOIN_UTIL_URL_H
diff --git a/src/util/validation.cpp b/src/util/validation.cpp
new file mode 100644
index 000000000000..00c66f66e8da
--- /dev/null
+++ b/src/util/validation.cpp
@@ -0,0 +1,20 @@
+// Copyright (c) 2009-2010 Satoshi Nakamoto
+// Copyright (c) 2009-2019 The Bitcoin Core developers
+// Distributed under the MIT software license, see the accompanying
+// file COPYING or http://www.opensource.org/licenses/mit-license.php.
+
+#include <util/validation.h>
+
+#include <consensus/validation.h>
+#include <tinyformat.h>
+
+/** Convert CValidationState to a human-readable message for logging */
+std::string FormatStateMessage(const CValidationState &state)
+{
+    return strprintf("%s%s (code %i)",
+        state.GetRejectReason(),
+        state.GetDebugMessage().empty() ? "" : ", "+state.GetDebugMessage(),
+        state.GetRejectCode());
+}
+
+const std::string strMessageMagic = "DarkCoin Signed Message:\n";
diff --git a/src/util/validation.h b/src/util/validation.h
new file mode 100644
index 000000000000..32559853ee61
--- /dev/null
+++ b/src/util/validation.h
@@ -0,0 +1,18 @@
+// Copyright (c) 2009-2010 Satoshi Nakamoto
+// Copyright (c) 2009-2019 The Bitcoin Core developers
+// Distributed under the MIT software license, see the accompanying
+// file COPYING or http://www.opensource.org/licenses/mit-license.php.
+
+#ifndef BITCOIN_UTIL_VALIDATION_H
+#define BITCOIN_UTIL_VALIDATION_H
+
+#include <string>
+
+class CValidationState;
+
+/** Convert CValidationState to a human-readable message for logging */
+std::string FormatStateMessage(const CValidationState &state);
+
+extern const std::string strMessageMagic;
+
+#endif // BITCOIN_UTIL_VALIDATION_H
diff --git a/src/util/vector.h b/src/util/vector.h
new file mode 100644
index 000000000000..dab65ded2ace
--- /dev/null
+++ b/src/util/vector.h
@@ -0,0 +1,51 @@
+// Copyright (c) 2019 The Bitcoin Core developers
+// Distributed under the MIT software license, see the accompanying
+// file COPYING or http://www.opensource.org/licenses/mit-license.php.
+
+#ifndef BITCOIN_UTIL_VECTOR_H
+#define BITCOIN_UTIL_VECTOR_H
+
+#include <initializer_list>
+#include <type_traits>
+#include <vector>
+
+/** Construct a vector with the specified elements.
+ *
+ * This is preferable over the list initializing constructor of std::vector:
+ * - It automatically infers the element type from its arguments.
+ * - If any arguments are rvalue references, they will be moved into the vector
+ *   (list initialization always copies).
+ */
+template<typename... Args>
+inline std::vector<typename std::common_type<Args...>::type> Vector(Args&&... args)
+{
+    std::vector<typename std::common_type<Args...>::type> ret;
+    ret.reserve(sizeof...(args));
+    // The line below uses the trick from https://www.experts-exchange.com/articles/32502/None-recursive-variadic-templates-with-std-initializer-list.html
+    (void)std::initializer_list<int>{(ret.emplace_back(std::forward<Args>(args)), 0)...};
+    return ret;
+}
+
+/** Concatenate two vectors, moving elements. */
+template<typename V>
+inline V Cat(V v1, V&& v2)
+{
+    v1.reserve(v1.size() + v2.size());
+    for (auto& arg : v2) {
+        v1.push_back(std::move(arg));
+    }
+    return v1;
+}
+
+/** Concatenate two vectors. */
+template<typename V>
+inline V Cat(V v1, const V& v2)
+{
+    v1.reserve(v1.size() + v2.size());
+    for (const auto& arg : v2) {
+        v1.push_back(arg);
+    }
+    return v1;
+}
+
+#endif // BITCOIN_UTIL_VECTOR_H
diff --git a/src/validation.cpp b/src/validation.cpp
index db2e36cd656d..b1f91c9b3a62 100644
--- a/src/validation.cpp
+++ b/src/validation.cpp
@@ -36,9 +36,10 @@
 #include <txmempool.h>
 #include <ui_interface.h>
 #include <undo.h>
-#include <util.h>
-#include <utilmoneystr.h>
-#include <utilstrencodings.h>
+#include <util/system.h>
+#include <util/moneystr.h>
+#include <util/strencodings.h>
+#include <util/validation.h>
 #include <validationinterface.h>
 #include <warnings.h>
 
@@ -269,8 +270,6 @@ static void CheckBlockIndex(const Consensus::Params& consensusParams);
 /** Constant stuff for coinbase transactions we create: */
 CScript COINBASE_FLAGS;
 
-const std::string strMessageMagic = "DarkCoin Signed Message:\n";
-
 // Internal stuff
 namespace {
     CBlockIndex *&pindexBestInvalid = g_chainstate.pindexBestInvalid;
@@ -525,16 +524,7 @@ static void LimitMempoolSize(CTxMemPool& pool, size_t limit, unsigned long age)
         pcoinsTip->Uncache(removed);
 }
 
-/** Convert CValidationState to a human-readable message for logging */
-std::string FormatStateMessage(const CValidationState &state)
-{
-    return strprintf("%s%s (code %i)",
-        state.GetRejectReason(),
-        state.GetDebugMessage().empty() ? "" : ", "+state.GetDebugMessage(),
-        state.GetRejectCode());
-}
-
-static bool IsCurrentForFeeEstimation()
+static bool IsCurrentForFeeEstimation() EXCLUSIVE_LOCKS_REQUIRED(cs_main)
 {
     AssertLockHeld(cs_main);
     if (IsInitialBlockDownload())
diff --git a/src/validation.h b/src/validation.h
index 0b9d1f72399f..5e3c127f36ea 100644
--- a/src/validation.h
+++ b/src/validation.h
@@ -152,7 +152,7 @@ extern CTxMemPool mempool;
 extern std::atomic_bool g_is_mempool_loaded;
 typedef std::unordered_map<uint256, CBlockIndex*, BlockHasher> BlockMap;
 typedef std::unordered_multimap<uint256, CBlockIndex*, BlockHasher> PrevBlockMap;
-extern BlockMap& mapBlockIndex;
+extern BlockMap& mapBlockIndex GUARDED_BY(cs_main);
 extern PrevBlockMap& mapPrevBlockIndex;
 extern uint64_t nLastBlockTx;
 extern uint64_t nLastBlockSize;
@@ -332,9 +332,6 @@ bool GetUTXOCoin(const COutPoint& outpoint, Coin& coin);
 int GetUTXOHeight(const COutPoint& outpoint);
 int GetUTXOConfirmations(const COutPoint& outpoint);
 
-/** Convert CValidationState to a human-readable message for logging */
-std::string FormatStateMessage(const CValidationState &state);
-
 /** Get the BIP9 state for a given deployment at the current tip. */
 ThresholdState VersionBitsTipState(const Consensus::Params& params, Consensus::DeploymentPos pos);
 
diff --git a/src/validationinterface.cpp b/src/validationinterface.cpp
index bac8dc54f05b..2639f03229f3 100644
--- a/src/validationinterface.cpp
+++ b/src/validationinterface.cpp
@@ -10,7 +10,7 @@
 #include <scheduler.h>
 #include <sync.h>
 #include <txmempool.h>
-#include <util.h>
+#include <util/system.h>
 #include <validation.h>
 
 #include <list>
diff --git a/src/wallet/coincontrol.cpp b/src/wallet/coincontrol.cpp
index 33ac24a06aab..0ac275d35847 100644
--- a/src/wallet/coincontrol.cpp
+++ b/src/wallet/coincontrol.cpp
@@ -5,7 +5,7 @@
 #include <wallet/coincontrol.h>
 #include <wallet/wallet.h>
 
-#include <util.h>
+#include <util/system.h>
 
 void CCoinControl::SetNull(bool fResetCoinType)
 {
diff --git a/src/wallet/coinselection.cpp b/src/wallet/coinselection.cpp
index d9721f8f75e6..d2ff97453347 100644
--- a/src/wallet/coinselection.cpp
+++ b/src/wallet/coinselection.cpp
@@ -3,8 +3,8 @@
 // file COPYING or http://www.opensource.org/licenses/mit-license.php.
 
 #include <wallet/coinselection.h>
-#include <util.h>
-#include <utilmoneystr.h>
+#include <util/system.h>
+#include <util/moneystr.h>
 
 #include <llmq/quorums_instantsend.h>
 #include <coinjoin/coinjoin.h>
diff --git a/src/wallet/crypter.cpp b/src/wallet/crypter.cpp
index 46f9334c16c8..a156c1c945d5 100644
--- a/src/wallet/crypter.cpp
+++ b/src/wallet/crypter.cpp
@@ -8,7 +8,7 @@
 #include <crypto/sha512.h>
 #include <script/script.h>
 #include <script/standard.h>
-#include <util.h>
+#include <util/system.h>
 
 #include <string>
 #include <vector>
diff --git a/src/wallet/db.cpp b/src/wallet/db.cpp
index 8347bc332453..ae8dc412075a 100644
--- a/src/wallet/db.cpp
+++ b/src/wallet/db.cpp
@@ -8,7 +8,7 @@
 #include <addrman.h>
 #include <hash.h>
 #include <protocol.h>
-#include <utilstrencodings.h>
+#include <util/strencodings.h>
 #include <wallet/walletutil.h>
 
 #include <stdint.h>
diff --git a/src/wallet/db.h b/src/wallet/db.h
index d12ad1ea59f4..5f8b1c04cd3d 100644
--- a/src/wallet/db.h
+++ b/src/wallet/db.h
@@ -11,7 +11,7 @@
 #include <serialize.h>
 #include <streams.h>
 #include <sync.h>
-#include <util.h>
+#include <util/system.h>
 #include <version.h>
 
 #include <atomic>
diff --git a/src/wallet/fees.cpp b/src/wallet/fees.cpp
index 1d58e2941c0e..eefe7df2bbf9 100644
--- a/src/wallet/fees.cpp
+++ b/src/wallet/fees.cpp
@@ -7,7 +7,7 @@
 
 #include <policy/policy.h>
 #include <txmempool.h>
-#include <util.h>
+#include <util/system.h>
 #include <validation.h>
 #include <wallet/coincontrol.h>
 #include <wallet/wallet.h>
diff --git a/src/wallet/init.cpp b/src/wallet/init.cpp
index f21e26e9f07a..5ad6ffb9cae5 100644
--- a/src/wallet/init.cpp
+++ b/src/wallet/init.cpp
@@ -7,8 +7,9 @@
 #include <keepass.h>
 #include <net.h>
 #include <scheduler.h>
-#include <util.h>
-#include <utilmoneystr.h>
+#include <util/error.h>
+#include <util/system.h>
+#include <util/moneystr.h>
 #include <validation.h>
 #include <walletinitinterface.h>
 #include <wallet/rpcwallet.h>
diff --git a/src/wallet/rpcdump.cpp b/src/wallet/rpcdump.cpp
index 3ca94f5c6735..ec793aff9ce8 100644
--- a/src/wallet/rpcdump.cpp
+++ b/src/wallet/rpcdump.cpp
@@ -10,8 +10,8 @@
 #include <script/script.h>
 #include <script/standard.h>
 #include <sync.h>
-#include <util.h>
-#include <utiltime.h>
+#include <util/system.h>
+#include <util/time.h>
 #include <wallet/wallet.h>
 #include <merkleblock.h>
 #include <core_io.h>
diff --git a/src/wallet/rpcwallet.cpp b/src/wallet/rpcwallet.cpp
index e47ba9d192d0..f44f20f36a90 100644
--- a/src/wallet/rpcwallet.cpp
+++ b/src/wallet/rpcwallet.cpp
@@ -19,8 +19,11 @@
 #include <rpc/util.h>
 #include <timedata.h>
 #include <txmempool.h>
-#include <util.h>
-#include <utilmoneystr.h>
+#include <util/fees.h>
+#include <util/system.h>
+#include <util/moneystr.h>
+#include <util/url.h>
+#include <util/validation.h>
 #include <validation.h>
 #include <wallet/coincontrol.h>
 #include <wallet/rpcwallet.h>
diff --git a/src/wallet/test/wallet_crypto_tests.cpp b/src/wallet/test/wallet_crypto_tests.cpp
index c3fc61ec430e..58dd03bcb0d8 100644
--- a/src/wallet/test/wallet_crypto_tests.cpp
+++ b/src/wallet/test/wallet_crypto_tests.cpp
@@ -3,7 +3,7 @@
 // file COPYING or http://www.opensource.org/licenses/mit-license.php.
 
 #include <test/test_dash.h>
-#include <utilstrencodings.h>
+#include <util/strencodings.h>
 #include <wallet/crypter.h>
 
 #include <vector>
diff --git a/src/wallet/wallet.cpp b/src/wallet/wallet.cpp
index e1631786b8bc..2ef5acb12b3d 100644
--- a/src/wallet/wallet.cpp
+++ b/src/wallet/wallet.cpp
@@ -26,7 +26,10 @@
 #include <script/sign.h>
 #include <timedata.h>
 #include <txmempool.h>
-#include <utilmoneystr.h>
+#include <util/error.h>
+#include <util/fees.h>
+#include <util/moneystr.h>
+#include <util/validation.h>
 #include <wallet/fees.h>
 #include <warnings.h>
 
diff --git a/src/wallet/wallet.h b/src/wallet/wallet.h
index addac4d8929e..c835b6c26718 100644
--- a/src/wallet/wallet.h
+++ b/src/wallet/wallet.h
@@ -13,8 +13,8 @@
 #include <streams.h>
 #include <tinyformat.h>
 #include <ui_interface.h>
-#include <util.h>
-#include <utilstrencodings.h>
+#include <util/system.h>
+#include <util/strencodings.h>
 #include <validationinterface.h>
 #include <script/ismine.h>
 #include <wallet/coincontrol.h>
diff --git a/src/wallet/walletdb.cpp b/src/wallet/walletdb.cpp
index 4445b7d1037d..d57cae8e3190 100644
--- a/src/wallet/walletdb.cpp
+++ b/src/wallet/walletdb.cpp
@@ -14,8 +14,8 @@
 #include <protocol.h>
 #include <serialize.h>
 #include <sync.h>
-#include <util.h>
-#include <utiltime.h>
+#include <util/system.h>
+#include <util/time.h>
 #include <wallet/wallet.h>
 #include <validation.h>
 
diff --git a/src/wallet/walletutil.h b/src/wallet/walletutil.h
index 62d0b5640f13..16067243031a 100644
--- a/src/wallet/walletutil.h
+++ b/src/wallet/walletutil.h
@@ -6,7 +6,7 @@
 #define BITCOIN_WALLET_WALLETUTIL_H
 
 #include <chainparamsbase.h>
-#include <util.h>
+#include <util/system.h>
 
 //! Get the path of the wallet directory.
 fs::path GetWalletDir();
diff --git a/src/warnings.cpp b/src/warnings.cpp
index 5f7d0df984a9..516bbbd90146 100644
--- a/src/warnings.cpp
+++ b/src/warnings.cpp
@@ -5,7 +5,7 @@
 
 #include <sync.h>
 #include <clientversion.h>
-#include <util.h>
+#include <util/system.h>
 #include <warnings.h>
 #include <hash.h>
 
diff --git a/src/zmq/zmqabstractnotifier.cpp b/src/zmq/zmqabstractnotifier.cpp
index 5057171b698c..218c382fc310 100644
--- a/src/zmq/zmqabstractnotifier.cpp
+++ b/src/zmq/zmqabstractnotifier.cpp
@@ -3,7 +3,7 @@
 // file COPYING or http://www.opensource.org/licenses/mit-license.php.
 
 #include <zmq/zmqabstractnotifier.h>
-#include <util.h>
+#include <util/system.h>
 
 
 CZMQAbstractNotifier::~CZMQAbstractNotifier()
diff --git a/src/zmq/zmqnotificationinterface.cpp b/src/zmq/zmqnotificationinterface.cpp
index 8cf64e3494a8..8d3ae1c22967 100644
--- a/src/zmq/zmqnotificationinterface.cpp
+++ b/src/zmq/zmqnotificationinterface.cpp
@@ -8,7 +8,7 @@
 #include <version.h>
 #include <validation.h>
 #include <streams.h>
-#include <util.h>
+#include <util/system.h>
 
 void zmqError(const char *str)
 {
diff --git a/src/zmq/zmqpublishnotifier.cpp b/src/zmq/zmqpublishnotifier.cpp
index 53e8aa67a2c9..0d1f7454fd0c 100644
--- a/src/zmq/zmqpublishnotifier.cpp
+++ b/src/zmq/zmqpublishnotifier.cpp
@@ -7,7 +7,7 @@
 #include <streams.h>
 #include <zmq/zmqpublishnotifier.h>
 #include <validation.h>
-#include <util.h>
+#include <util/system.h>
 
 static std::multimap<std::string, CZMQAbstractPublishNotifier*> mapPublishNotifiers;
 
diff --git a/test/lint/lint-circular-dependencies.sh b/test/lint/lint-circular-dependencies.sh
index dfe3486e730a..5f7efce83757 100755
--- a/test/lint/lint-circular-dependencies.sh
+++ b/test/lint/lint-circular-dependencies.sh
@@ -9,7 +9,7 @@
 export LC_ALL=C
 
 EXPECTED_CIRCULAR_DEPENDENCIES=(
-    "chainparamsbase -> util -> chainparamsbase"
+    "chainparamsbase -> util/system -> chainparamsbase"
     "checkpoints -> validation -> checkpoints"
     "index/txindex -> validation -> index/txindex"
     "policy/fees -> txmempool -> policy/fees"
@@ -78,7 +78,7 @@ EXPECTED_CIRCULAR_DEPENDENCIES=(
     "llmq/quorums_signing -> llmq/quorums_signing_shares -> llmq/quorums_signing"
     "llmq/quorums_signing -> net_processing -> llmq/quorums_signing"
     "llmq/quorums_signing_shares -> net_processing -> llmq/quorums_signing_shares"
-    "logging -> util -> logging"
+    "logging -> util/system -> logging"
     "masternode/masternode-payments -> validation -> masternode/masternode-payments"
     "net -> netmessagemaker -> net"
     "net_processing -> spork -> net_processing"
@@ -96,9 +96,9 @@ EXPECTED_CIRCULAR_DEPENDENCIES=(
     "httpserver -> init -> httpserver"
     "init -> llmq/quorums_init -> llmq/quorums_signing_shares -> init"
     "llmq/quorums_dkgsession -> llmq/quorums_dkgsessionmgr -> llmq/quorums_dkgsessionhandler -> llmq/quorums_dkgsession"
-    "logging -> util -> random -> logging"
-    "logging -> util -> sync -> logging"
-    "logging -> util -> stacktraces -> logging"
+    "logging -> util/system -> random -> logging"
+    "logging -> util/system -> sync -> logging"
+    "logging -> util/system -> stacktraces -> logging"
     "coinjoin/coinjoin-client -> coinjoin/coinjoin-util -> wallet/wallet -> coinjoin/coinjoin-client"
     "qt/appearancewidget -> qt/guiutil -> qt/optionsdialog -> qt/appearancewidget"
     "qt/bitcoinaddressvalidator -> qt/guiutil -> qt/qvalidatedlineedit -> qt/bitcoinaddressvalidator"
diff --git a/test/lint/lint-format-strings.py b/test/lint/lint-format-strings.py
index 6c6d01a22f9b..5a1adf61995f 100755
--- a/test/lint/lint-format-strings.py
+++ b/test/lint/lint-format-strings.py
@@ -24,8 +24,8 @@
     ("src/stacktraces.cpp", "strprintf(fmtStr, i, si.pc, lstr, fstr)"),
     ("src/statsd_client.cpp", "snprintf(d->errmsg, sizeof(d->errmsg), \"could not create socket, err=%m\")"),
     ("src/statsd_client.cpp", "snprintf(d->errmsg, sizeof(d->errmsg), \"sendto server fail, host=%s:%d, err=%m\", d->host.c_str(), d->port)"),
-    ("src/util.cpp", "strprintf(_(COPYRIGHT_HOLDERS), _(COPYRIGHT_HOLDERS_SUBSTITUTION))"),
-    ("src/util.cpp", "strprintf(COPYRIGHT_HOLDERS, COPYRIGHT_HOLDERS_SUBSTITUTION)"),
+    ("src/util/system.cpp", "strprintf(_(COPYRIGHT_HOLDERS), _(COPYRIGHT_HOLDERS_SUBSTITUTION))"),
+    ("src/util/system.cpp", "strprintf(COPYRIGHT_HOLDERS, COPYRIGHT_HOLDERS_SUBSTITUTION)"),
     ("src/wallet/wallet.h",  "WalletLogPrintf(std::string fmt, Params... parameters)"),
     ("src/wallet/wallet.h", "LogPrintf((\"%s \" + fmt).c_str(), GetDisplayName(), parameters...)"),
     ("src/logging.h", "LogPrintf(const char* fmt, const Args&... args)"),
diff --git a/test/lint/lint-locale-dependence.sh b/test/lint/lint-locale-dependence.sh
index 36ff6133fc58..938fadfc79b2 100755
--- a/test/lint/lint-locale-dependence.sh
+++ b/test/lint/lint-locale-dependence.sh
@@ -32,18 +32,18 @@ KNOWN_VIOLATIONS=(
     "src/torcontrol.cpp:.*strtol"
     "src/uint256.cpp:.*isspace"
     "src/uint256.cpp:.*tolower"
-    "src/util.cpp:.*atoi"
-    "src/util.cpp:.*fprintf"
-    "src/util.cpp:.*tolower"
-    "src/utilmoneystr.cpp:.*isdigit"
-    "src/utilmoneystr.cpp:.*isspace"
-    "src/utilstrencodings.cpp:.*atoi"
-    "src/utilstrencodings.cpp:.*isspace"
-    "src/utilstrencodings.cpp:.*strtol"
-    "src/utilstrencodings.cpp:.*strtoll"
-    "src/utilstrencodings.cpp:.*strtoul"
-    "src/utilstrencodings.cpp:.*strtoull"
-    "src/utilstrencodings.h:.*atoi"
+    "src/util/system.cpp:.*atoi"
+    "src/util/system.cpp:.*fprintf"
+    "src/util/system.cpp:.*tolower"
+    "src/util/moneystr.cpp:.*isdigit"
+    "src/util/moneystr.cpp:.*isspace"
+    "src/util/strencodings.cpp:.*atoi"
+    "src/util/strencodings.cpp:.*isspace"
+    "src/util/strencodings.cpp:.*strtol"
+    "src/util/strencodings.cpp:.*strtoll"
+    "src/util/strencodings.cpp:.*strtoul"
+    "src/util/strencodings.cpp:.*strtoull"
+    "src/util/strencodings.h:.*atoi"
     "src/wallet/wallet.cpp:.*atoi"
 )