🦀 Mini-ZK: A Bare-Bones ZK Proof System in Rust

Mini-ZK is a Zero-Knowledge (ZK) framework built from scratch in Rust. Unlike production-grade libraries (Noir, Circom) that treat the Prover/Verifier relationship as a "black box," Nano-ZK exposes the underlying plumbing of R1CS (Rank-1 Constraint Systems) and Circuit Arithmetization.

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🏗 Architecture Overview

The system is split into three distinct layers, mimicking the workflow of modern ZK-SNARKs:

1. The Circuit (High-Level Logic)

The Circuit struct is the "blueprint." It defines the inputs (Private Witness) and the gates (Addition, Multiplication, Hashing) that represent the business logic. It is stateless; once defined, the wires do not change.

2. R1CS (Rank-1 Constraint System)

The "Translator." It flattens the circuit into a series of mathematical constraints. Every gate is converted into a structured equation: $$Left_Value \circ Right_Value = Output_Value$$ The R1CS ensures that for any given set of inputs, the mathematical "pressure" balances across all constraints.

3. The Prover & Verifier

• Prover: Iterates through the circuit, generates the Witness (the values on every wire), and serializes them into a .proof binary.
• Verifier: Reads the .proof and the public constraints, then executes an is_satisfied check to confirm the logic holds without knowing the private inputs.

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🚀 Key Features

• Custom Arithmetic Gates: Support for Addition and Multiplication.
• Primitive Range Proofs: Foundational logic for inequality checks (e.g., Age > 18).
• Merkle Tree Integration: Proof of membership for blockchain-style transaction verification.
• Rust-Native Performance: Uses serde for efficient proof serialization and bigint for arbitrary-precision arithmetic.

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🛠 Project Structure

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├── src/
│   ├── main.rs          # Entry point: Example proof implementations
│   ├── circuit.rs       # The Circuit blueprint and Proof Generator
│   ├── r1cs.rs          # Constraint system logic and 'is_satisfied' checker
│   ├── merkle.rs        # Utility: Merkle Tree & Path generation
│   └── hash.rs          # Utility: Mock hash functions for debugging
└── Cargo.toml           # Dependencies (rand, sha2, serde, bincode)

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🙏Acknowledgement

This project was inspired by the original Mini-ZK implementation by Luis Soares
(https://github.com/luishsr/zk-mini).

His work provided the conceptual foundation for the circuit-to-R1CS pipeline and the first-principles approach to Zero-Knowledge system design that this repository builds on.

This Rust implementation is an independent, from-scratch re-engineering focused on clarity, extensibility, and systems-level understanding of ZK proof mechanics.

🧾License

This project is licensed under the MIT License. See LICENSE for details.