diff --git a/mesh/v1alpha1/config.pb.go b/mesh/v1alpha1/config.pb.go
index 04cfb65148..c1e92f1999 100644
--- a/mesh/v1alpha1/config.pb.go
+++ b/mesh/v1alpha1/config.pb.go
@@ -175,6 +175,10 @@ type MeshConfig struct {
 	// for k8s service account JWT, so that K8s API server mounts k8s service account JWT to envoy container, which
 	// will be used to generate key/cert eventually. This isn't supported for non-k8s case.
 	EnableSdsTokenMount bool `protobuf:"varint,23,opt,name=enable_sds_token_mount,json=enableSdsTokenMount,proto3" json:"enable_sds_token_mount,omitempty"`
+	// The trust domain corresponds to the trust root of a system.
+	// Refer to https://github.com/spiffe/spiffe/blob/master/standards/SPIFFE-ID.md#21-trust-domain
+	// Fallback to old identity format(without trust domain) if not set.
+	TrustDomain string `protobuf:"bytes,26,opt,name=trust_domain,json=trustDomain,proto3" json:"trust_domain,omitempty"`
 }
 
 func (m *MeshConfig) Reset()                    { *m = MeshConfig{} }
@@ -315,6 +319,13 @@ func (m *MeshConfig) GetEnableSdsTokenMount() bool {
 	return false
 }
 
+func (m *MeshConfig) GetTrustDomain() string {
+	if m != nil {
+		return m.TrustDomain
+	}
+	return ""
+}
+
 // ConfigSource describes information about a configuration store inside a
 // mesh. A single control plane instance can interact with one or more data
 // sources.
@@ -525,6 +536,14 @@ func (m *MeshConfig) MarshalTo(dAtA []byte) (int, error) {
 		}
 		i++
 	}
+	if len(m.TrustDomain) > 0 {
+		dAtA[i] = 0xd2
+		i++
+		dAtA[i] = 0x1
+		i++
+		i = encodeVarintConfig(dAtA, i, uint64(len(m.TrustDomain)))
+		i += copy(dAtA[i:], m.TrustDomain)
+	}
 	return i, nil
 }
 
@@ -643,6 +662,10 @@ func (m *MeshConfig) Size() (n int) {
 	if m.PolicyCheckFailOpen {
 		n += 3
 	}
+	l = len(m.TrustDomain)
+	if l > 0 {
+		n += 2 + l + sovConfig(uint64(l))
+	}
 	return n
 }
 
@@ -1178,6 +1201,35 @@ func (m *MeshConfig) Unmarshal(dAtA []byte) error {
 				}
 			}
 			m.PolicyCheckFailOpen = bool(v != 0)
+		case 26:
+			if wireType != 2 {
+				return fmt.Errorf("proto: wrong wireType = %d for field TrustDomain", wireType)
+			}
+			var stringLen uint64
+			for shift := uint(0); ; shift += 7 {
+				if shift >= 64 {
+					return ErrIntOverflowConfig
+				}
+				if iNdEx >= l {
+					return io.ErrUnexpectedEOF
+				}
+				b := dAtA[iNdEx]
+				iNdEx++
+				stringLen |= (uint64(b) & 0x7F) << shift
+				if b < 0x80 {
+					break
+				}
+			}
+			intStringLen := int(stringLen)
+			if intStringLen < 0 {
+				return ErrInvalidLengthConfig
+			}
+			postIndex := iNdEx + intStringLen
+			if postIndex > l {
+				return io.ErrUnexpectedEOF
+			}
+			m.TrustDomain = string(dAtA[iNdEx:postIndex])
+			iNdEx = postIndex
 		default:
 			iNdEx = preIndex
 			skippy, err := skipConfig(dAtA[iNdEx:])
@@ -1419,58 +1471,59 @@ var (
 func init() { proto.RegisterFile("mesh/v1alpha1/config.proto", fileDescriptorConfig) }
 
 var fileDescriptorConfig = []byte{
-	// 838 bytes of a gzipped FileDescriptorProto
-	0x1f, 0x8b, 0x08, 0x00, 0x00, 0x00, 0x00, 0x00, 0x02, 0xff, 0x84, 0x54, 0xdd, 0x4e, 0x23, 0x37,
-	0x18, 0xdd, 0x81, 0x2c, 0x84, 0x2f, 0x7f, 0x83, 0x53, 0x58, 0x43, 0x25, 0x9a, 0x52, 0x95, 0x46,
-	0xa8, 0x9a, 0x68, 0x83, 0x7a, 0xd1, 0x4b, 0x08, 0x9b, 0x2e, 0x51, 0x58, 0xd0, 0x64, 0xb8, 0xe9,
-	0x8d, 0x35, 0xcc, 0x38, 0x33, 0x16, 0x8e, 0x3d, 0x1a, 0x7b, 0xb6, 0xbb, 0xcf, 0xd4, 0x17, 0xe9,
-	0x65, 0x1f, 0xa1, 0xe2, 0x49, 0xaa, 0xb1, 0x27, 0x24, 0x48, 0x91, 0xf6, 0xd2, 0xe7, 0x1c, 0xfb,
-	0x3b, 0xfe, 0xce, 0x67, 0xc3, 0xf1, 0x82, 0xaa, 0x74, 0xf0, 0xf9, 0x7d, 0xc8, 0xb3, 0x34, 0x7c,
-	0x3f, 0x88, 0xa4, 0x98, 0xb3, 0xc4, 0xcb, 0x72, 0xa9, 0x25, 0xea, 0x32, 0xa5, 0x99, 0xf4, 0x4a,
-	0x85, 0xb7, 0x54, 0x1c, 0x9f, 0x24, 0x52, 0x26, 0x9c, 0x0e, 0x8c, 0xe4, 0xb1, 0x98, 0x0f, 0xe2,
-	0x22, 0x0f, 0x35, 0x93, 0xc2, 0x6e, 0x3a, 0x3e, 0x7a, 0x7d, 0x60, 0x96, 0xcb, 0x2f, 0x5f, 0x2b,
-	0xea, 0x5c, 0x50, 0xfd, 0x97, 0xcc, 0x9f, 0x98, 0x48, 0x96, 0x82, 0x8b, 0x41, 0x4c, 0x95, 0x66,
-	0xc2, 0x9c, 0x40, 0xf2, 0x82, 0x53, 0xab, 0x3d, 0xfd, 0x7b, 0x0f, 0xe0, 0x96, 0xaa, 0x74, 0x64,
-	0x0c, 0xa1, 0x5f, 0x01, 0x2d, 0xd8, 0x17, 0x9a, 0x93, 0x28, 0xa5, 0xd1, 0x13, 0x51, 0x34, 0xff,
-	0x4c, 0x73, 0xec, 0xf4, 0x9c, 0xfe, 0x9e, 0xef, 0x1a, 0x66, 0x54, 0x12, 0x33, 0x83, 0x23, 0x0f,
-	0xba, 0x56, 0x9d, 0xd3, 0x4c, 0xe6, 0x7a, 0x29, 0xdf, 0x32, 0xf2, 0x7d, 0x43, 0xf9, 0x86, 0xa9,
-	0xf4, 0x43, 0x38, 0x88, 0x99, 0x0a, 0x1f, 0x39, 0x25, 0x99, 0xe4, 0x2c, 0xfa, 0x6a, 0xcb, 0x28,
-	0xbc, 0xdd, 0x73, 0xfa, 0x75, 0xbf, 0x5b, 0x91, 0xf7, 0x86, 0x33, 0x85, 0x14, 0x3a, 0x87, 0x7d,
-	0x73, 0x37, 0xc2, 0x99, 0xd2, 0x54, 0x90, 0xf2, 0x38, 0x5c, 0xeb, 0x39, 0xfd, 0xb7, 0x7e, 0xc7,
-	0x10, 0x53, 0x83, 0xdf, 0xcb, 0x5c, 0xa3, 0x33, 0xb0, 0x10, 0x49, 0xb5, 0xce, 0xac, 0xf2, 0xad,
-	0x51, 0xb6, 0x0c, 0xfc, 0x51, 0xeb, 0xcc, 0xe8, 0xae, 0xa0, 0x13, 0x49, 0x21, 0x68, 0xa4, 0x89,
-	0x66, 0x0b, 0x2a, 0x0b, 0x8d, 0x77, 0x7a, 0x4e, 0xbf, 0x31, 0x3c, 0xf2, 0x6c, 0xd7, 0xbd, 0x65,
-	0xd7, 0xbd, 0xeb, 0xaa, 0xeb, 0x7e, 0xbb, 0xda, 0x11, 0xd8, 0x0d, 0xe8, 0x27, 0x68, 0x31, 0x91,
-	0xe4, 0x54, 0x29, 0x12, 0xf1, 0x50, 0x29, 0xbc, 0x6b, 0x6e, 0xdd, 0xac, 0xc0, 0x51, 0x89, 0xa1,
-	0x5f, 0xa0, 0xb3, 0x14, 0x95, 0xbd, 0x61, 0x11, 0xc5, 0x75, 0x23, 0x6b, 0x57, 0xf0, 0xcc, 0xa2,
-	0x68, 0x01, 0xef, 0x5e, 0x4e, 0x93, 0x42, 0xe7, 0x92, 0x73, 0x9a, 0x93, 0x85, 0x8c, 0x29, 0xde,
-	0xeb, 0x39, 0xfd, 0xf6, 0xf0, 0x37, 0x6f, 0xc3, 0x90, 0x78, 0xab, 0xe4, 0xbc, 0x9b, 0xaa, 0xee,
-	0xcb, 0xee, 0x5b, 0x19, 0x53, 0xff, 0x80, 0x6d, 0x82, 0xd1, 0x1d, 0x34, 0xc2, 0x42, 0xa7, 0x55,
-	0x0a, 0x18, 0x4c, 0x89, 0xf3, 0x6f, 0x95, 0xb8, 0x2c, 0x74, 0x6a, 0xb3, 0xb9, 0xda, 0xc2, 0x8e,
-	0x0f, 0xe1, 0xcb, 0x1a, 0xfd, 0x0c, 0x6d, 0x2a, 0x4c, 0xb0, 0x3a, 0x0f, 0x23, 0x26, 0x12, 0xdc,
-	0x34, 0x91, 0xb6, 0x2c, 0x1a, 0x58, 0xb0, 0x0c, 0x28, 0x8c, 0xa2, 0xf2, 0x96, 0x5c, 0x26, 0x64,
-	0xce, 0x38, 0xc5, 0x2d, 0xd3, 0x8f, 0x96, 0x85, 0xa7, 0x32, 0x19, 0x33, 0x4e, 0xd1, 0x1f, 0xd0,
-	0x8e, 0xe9, 0x3c, 0x2c, 0xb8, 0x26, 0xf6, 0xa5, 0xe0, 0xb6, 0xc9, 0xa7, 0xb7, 0xd1, 0xe2, 0x7d,
-	0x19, 0xae, 0xf5, 0xe8, 0xb7, 0xaa, 0x7d, 0xd5, 0x3c, 0x5f, 0xc3, 0x0f, 0x95, 0xaf, 0x88, 0x33,
-	0x2a, 0x34, 0x51, 0x2c, 0x7e, 0x3d, 0x7c, 0xb8, 0x6b, 0x8c, 0x7e, 0x6f, 0x65, 0x23, 0xa3, 0x9a,
-	0xb1, 0x78, 0x7d, 0x08, 0x51, 0x0f, 0x9a, 0x2a, 0x56, 0xa4, 0x88, 0x15, 0xc9, 0x42, 0x9d, 0xe2,
-	0xef, 0x8c, 0x67, 0x50, 0xb1, 0x7a, 0x88, 0xd5, 0x7d, 0xa8, 0x53, 0xf4, 0x11, 0xda, 0xd6, 0x28,
-	0x51, 0xb2, 0xc8, 0x23, 0xaa, 0xf0, 0x61, 0x6f, 0xbb, 0xdf, 0x18, 0xfe, 0xb8, 0xd1, 0xb0, 0x35,
-	0x37, 0x33, 0x4a, 0xbf, 0x15, 0xad, 0xad, 0x14, 0xba, 0x80, 0xc3, 0xca, 0x71, 0x59, 0x52, 0xcb,
-	0x27, 0x2a, 0xc8, 0x42, 0x16, 0x42, 0xe3, 0x77, 0xf6, 0x91, 0x58, 0x76, 0x16, 0xab, 0xa0, 0xe4,
-	0x6e, 0x4b, 0xaa, 0x7c, 0x24, 0xeb, 0x7d, 0x95, 0xf9, 0x22, 0xd4, 0x18, 0x1b, 0x97, 0x9d, 0x55,
-	0x67, 0x0d, 0x5c, 0x16, 0x58, 0xbf, 0x3f, 0x99, 0x87, 0x8c, 0x13, 0x99, 0x51, 0x81, 0x8f, 0x6c,
-	0x81, 0x6c, 0x75, 0xf3, 0x71, 0xc8, 0xf8, 0x5d, 0x46, 0xc5, 0xe9, 0xef, 0x70, 0xb0, 0x71, 0xc0,
-	0xd0, 0x2e, 0x6c, 0xdf, 0x8d, 0xc7, 0xee, 0x1b, 0xd4, 0x80, 0xdd, 0xeb, 0x0f, 0xe3, 0xcb, 0x87,
-	0x69, 0xe0, 0x3a, 0x08, 0x60, 0x67, 0x16, 0xf8, 0x37, 0xa3, 0xc0, 0xdd, 0x3a, 0x3d, 0x03, 0x58,
-	0x0d, 0x0e, 0xaa, 0x43, 0xed, 0xd3, 0xdd, 0xa7, 0x0f, 0xee, 0x1b, 0xd4, 0x06, 0xb8, 0x7d, 0x08,
-	0x1e, 0x2e, 0xa7, 0x24, 0x98, 0xce, 0x5c, 0x67, 0x52, 0xab, 0x37, 0xdc, 0xe6, 0xa4, 0x56, 0xef,
-	0xb8, 0xee, 0xa4, 0x56, 0x77, 0xdd, 0xfd, 0x49, 0xad, 0xbe, 0xef, 0xa2, 0x49, 0xad, 0x8e, 0xdc,
-	0xee, 0xa4, 0x56, 0x3f, 0x70, 0x0f, 0x4f, 0x15, 0x34, 0xd7, 0x7b, 0x87, 0x30, 0xec, 0x86, 0x71,
-	0x5c, 0xda, 0xaa, 0xfe, 0xa8, 0xe5, 0x12, 0xdd, 0x40, 0x53, 0xf3, 0xf2, 0xd5, 0x69, 0xcd, 0x44,
-	0xa2, 0xcc, 0x9f, 0xd4, 0x18, 0x9e, 0x55, 0x71, 0xac, 0x3e, 0xc8, 0x65, 0x28, 0x17, 0x5e, 0x30,
-	0x9d, 0xcd, 0x2a, 0xb5, 0xdf, 0xd0, 0x5c, 0x2d, 0x17, 0x57, 0xfd, 0x7f, 0x9e, 0x4f, 0x9c, 0x7f,
-	0x9f, 0x4f, 0x9c, 0xff, 0x9e, 0x4f, 0x9c, 0x3f, 0x8f, 0xed, 0x09, 0x4c, 0x0e, 0xc2, 0x8c, 0x0d,
-	0x5e, 0x7d, 0xc2, 0x8f, 0x3b, 0xe6, 0xdb, 0xb8, 0xf8, 0x3f, 0x00, 0x00, 0xff, 0xff, 0x4a, 0x5f,
-	0x27, 0x27, 0xed, 0x05, 0x00, 0x00,
+	// 857 bytes of a gzipped FileDescriptorProto
+	0x1f, 0x8b, 0x08, 0x00, 0x00, 0x00, 0x00, 0x00, 0x02, 0xff, 0x84, 0x54, 0x5d, 0x4f, 0x23, 0x37,
+	0x14, 0xdd, 0x81, 0x2c, 0x84, 0x9b, 0x0f, 0x06, 0xa7, 0xb0, 0x26, 0x95, 0x68, 0x96, 0xaa, 0x34,
+	0x42, 0xd5, 0x44, 0x1b, 0xd4, 0x87, 0x3e, 0x42, 0xd8, 0x74, 0x89, 0xc2, 0x82, 0x26, 0xe1, 0xa5,
+	0x2f, 0xd6, 0x30, 0xe3, 0x64, 0x2c, 0x1c, 0x7b, 0x64, 0x7b, 0xb6, 0xbb, 0xff, 0xb0, 0x4f, 0x55,
+	0x7f, 0x42, 0xc5, 0x2f, 0xa9, 0xc6, 0x9e, 0x90, 0x20, 0x45, 0xea, 0xa3, 0xcf, 0x39, 0xbe, 0xf7,
+	0xf8, 0xde, 0xeb, 0x0b, 0xed, 0x05, 0xd5, 0x69, 0xef, 0xcb, 0x87, 0x88, 0x67, 0x69, 0xf4, 0xa1,
+	0x17, 0x4b, 0x31, 0x63, 0xf3, 0x20, 0x53, 0xd2, 0x48, 0xd4, 0x62, 0xda, 0x30, 0x19, 0x14, 0x8a,
+	0x60, 0xa9, 0x68, 0x9f, 0xcc, 0xa5, 0x9c, 0x73, 0xda, 0xb3, 0x92, 0xc7, 0x7c, 0xd6, 0x4b, 0x72,
+	0x15, 0x19, 0x26, 0x85, 0xbb, 0xd4, 0x3e, 0x7e, 0x1d, 0x30, 0x53, 0xf2, 0xeb, 0xb7, 0x92, 0x3a,
+	0x17, 0xd4, 0xfc, 0x29, 0xd5, 0x13, 0x13, 0xf3, 0xa5, 0xe0, 0xa2, 0x97, 0x50, 0x6d, 0x98, 0xb0,
+	0x11, 0x88, 0xca, 0x39, 0x75, 0xda, 0xd3, 0xbf, 0xf7, 0x00, 0x6e, 0xa9, 0x4e, 0x07, 0xd6, 0x10,
+	0xfa, 0x05, 0xd0, 0x82, 0x7d, 0xa5, 0x8a, 0xc4, 0x29, 0x8d, 0x9f, 0x88, 0xa6, 0xea, 0x0b, 0x55,
+	0xd8, 0xeb, 0x78, 0xdd, 0xbd, 0xd0, 0xb7, 0xcc, 0xa0, 0x20, 0x26, 0x16, 0x47, 0x01, 0xb4, 0x9c,
+	0x5a, 0xd1, 0x4c, 0x2a, 0xb3, 0x94, 0x6f, 0x59, 0xf9, 0x81, 0xa5, 0x42, 0xcb, 0x94, 0xfa, 0x3e,
+	0x1c, 0x26, 0x4c, 0x47, 0x8f, 0x9c, 0x92, 0x4c, 0x72, 0x16, 0x7f, 0x73, 0x69, 0x34, 0xde, 0xee,
+	0x78, 0xdd, 0x6a, 0xd8, 0x2a, 0xc9, 0x7b, 0xcb, 0xd9, 0x44, 0x1a, 0x9d, 0xc3, 0x81, 0x7d, 0x1b,
+	0xe1, 0x4c, 0x1b, 0x2a, 0x48, 0x11, 0x0e, 0x57, 0x3a, 0x5e, 0xf7, 0x6d, 0xb8, 0x6f, 0x89, 0xb1,
+	0xc5, 0xef, 0xa5, 0x32, 0xe8, 0x0c, 0x1c, 0x44, 0x52, 0x63, 0x32, 0xa7, 0x7c, 0x6b, 0x95, 0x0d,
+	0x0b, 0x7f, 0x32, 0x26, 0xb3, 0xba, 0x2b, 0xd8, 0x8f, 0xa5, 0x10, 0x34, 0x36, 0xc4, 0xb0, 0x05,
+	0x95, 0xb9, 0xc1, 0x3b, 0x1d, 0xaf, 0x5b, 0xeb, 0x1f, 0x07, 0xae, 0xea, 0xc1, 0xb2, 0xea, 0xc1,
+	0x75, 0x59, 0xf5, 0xb0, 0x59, 0xde, 0x98, 0xba, 0x0b, 0xe8, 0x47, 0x68, 0x30, 0x31, 0x57, 0x54,
+	0x6b, 0x12, 0xf3, 0x48, 0x6b, 0xbc, 0x6b, 0x5f, 0x5d, 0x2f, 0xc1, 0x41, 0x81, 0xa1, 0x9f, 0x61,
+	0x7f, 0x29, 0x2a, 0x6a, 0xc3, 0x62, 0x8a, 0xab, 0x56, 0xd6, 0x2c, 0xe1, 0x89, 0x43, 0xd1, 0x02,
+	0xde, 0xbd, 0x44, 0x93, 0xc2, 0x28, 0xc9, 0x39, 0x55, 0x64, 0x21, 0x13, 0x8a, 0xf7, 0x3a, 0x5e,
+	0xb7, 0xd9, 0xff, 0x35, 0xd8, 0x30, 0x24, 0xc1, 0xaa, 0x73, 0xc1, 0x4d, 0x99, 0xf7, 0xe5, 0xf6,
+	0xad, 0x4c, 0x68, 0x78, 0xc8, 0x36, 0xc1, 0xe8, 0x0e, 0x6a, 0x51, 0x6e, 0xd2, 0xb2, 0x0b, 0x18,
+	0x6c, 0x8a, 0xf3, 0xff, 0x4b, 0x71, 0x99, 0x9b, 0xd4, 0xf5, 0xe6, 0x6a, 0x0b, 0x7b, 0x21, 0x44,
+	0x2f, 0x67, 0xf4, 0x13, 0x34, 0xa9, 0xb0, 0x8d, 0x35, 0x2a, 0x8a, 0x99, 0x98, 0xe3, 0xba, 0x6d,
+	0x69, 0xc3, 0xa1, 0x53, 0x07, 0x16, 0x0d, 0x8a, 0xe2, 0xb8, 0x78, 0x25, 0x97, 0x73, 0x32, 0x63,
+	0x9c, 0xe2, 0x86, 0xad, 0x47, 0xc3, 0xc1, 0x63, 0x39, 0x1f, 0x32, 0x4e, 0xd1, 0xef, 0xd0, 0x4c,
+	0xe8, 0x2c, 0xca, 0xb9, 0x21, 0xee, 0xa7, 0xe0, 0xa6, 0xed, 0x4f, 0x67, 0xa3, 0xc5, 0xfb, 0xa2,
+	0xb9, 0xce, 0x63, 0xd8, 0x28, 0xef, 0x95, 0xf3, 0x7c, 0x0d, 0x3f, 0x94, 0xbe, 0x62, 0xce, 0xa8,
+	0x30, 0x44, 0xb3, 0xe4, 0xf5, 0xf0, 0xe1, 0x96, 0x35, 0xfa, 0xbd, 0x93, 0x0d, 0xac, 0x6a, 0xc2,
+	0x92, 0xf5, 0x21, 0x44, 0x1d, 0xa8, 0xeb, 0x44, 0x93, 0x3c, 0xd1, 0x24, 0x8b, 0x4c, 0x8a, 0xbf,
+	0xb3, 0x9e, 0x41, 0x27, 0xfa, 0x21, 0xd1, 0xf7, 0x91, 0x49, 0xd1, 0x27, 0x68, 0x3a, 0xa3, 0x44,
+	0xcb, 0x5c, 0xc5, 0x54, 0xe3, 0xa3, 0xce, 0x76, 0xb7, 0xd6, 0x7f, 0xbf, 0xd1, 0xb0, 0x33, 0x37,
+	0xb1, 0xca, 0xb0, 0x11, 0xaf, 0x9d, 0x34, 0xba, 0x80, 0xa3, 0xd2, 0x71, 0x91, 0xd2, 0xc8, 0x27,
+	0x2a, 0xc8, 0x42, 0xe6, 0xc2, 0xe0, 0x77, 0xee, 0x93, 0x38, 0x76, 0x92, 0xe8, 0x69, 0xc1, 0xdd,
+	0x16, 0x54, 0xf1, 0x49, 0xd6, 0xeb, 0x2a, 0xd5, 0x22, 0x32, 0x18, 0x5b, 0x97, 0xfb, 0xab, 0xca,
+	0x5a, 0xb8, 0x48, 0xb0, 0xfe, 0x7e, 0x32, 0x8b, 0x18, 0x27, 0x32, 0xa3, 0x02, 0x1f, 0xbb, 0x04,
+	0xd9, 0xea, 0xe5, 0xc3, 0x88, 0xf1, 0xbb, 0x8c, 0x0a, 0xf4, 0x1e, 0xea, 0x46, 0xe5, 0xda, 0x90,
+	0x44, 0x2e, 0x22, 0x26, 0x70, 0xdb, 0xc6, 0xae, 0x59, 0xec, 0xda, 0x42, 0xa7, 0xbf, 0xc1, 0xe1,
+	0xc6, 0x19, 0x44, 0xbb, 0xb0, 0x7d, 0x37, 0x1c, 0xfa, 0x6f, 0x50, 0x0d, 0x76, 0xaf, 0x3f, 0x0e,
+	0x2f, 0x1f, 0xc6, 0x53, 0xdf, 0x43, 0x00, 0x3b, 0x93, 0x69, 0x78, 0x33, 0x98, 0xfa, 0x5b, 0xa7,
+	0x67, 0x00, 0xab, 0xd9, 0x42, 0x55, 0xa8, 0x7c, 0xbe, 0xfb, 0xfc, 0xd1, 0x7f, 0x83, 0x9a, 0x00,
+	0xb7, 0x0f, 0xd3, 0x87, 0xcb, 0x31, 0x99, 0x8e, 0x27, 0xbe, 0x37, 0xaa, 0x54, 0x6b, 0x7e, 0x7d,
+	0x54, 0xa9, 0xee, 0xfb, 0xfe, 0xa8, 0x52, 0xf5, 0xfd, 0x83, 0x51, 0xa5, 0x7a, 0xe0, 0xa3, 0x51,
+	0xa5, 0x8a, 0xfc, 0xd6, 0xa8, 0x52, 0x3d, 0xf4, 0x8f, 0x4e, 0x35, 0xd4, 0xd7, 0xcb, 0x8b, 0x30,
+	0xec, 0x46, 0x49, 0x52, 0xd8, 0x2a, 0xd7, 0xd8, 0xf2, 0x88, 0x6e, 0xa0, 0x6e, 0x78, 0xf1, 0x31,
+	0x8d, 0x61, 0x62, 0xae, 0xed, 0xda, 0xaa, 0xf5, 0xcf, 0xca, 0x8e, 0xad, 0x76, 0xe8, 0xb2, 0x6f,
+	0x17, 0xc1, 0x74, 0x3c, 0x99, 0x94, 0xea, 0xb0, 0x66, 0xb8, 0x5e, 0x1e, 0xae, 0xba, 0x7f, 0x3d,
+	0x9f, 0x78, 0xff, 0x3c, 0x9f, 0x78, 0xff, 0x3e, 0x9f, 0x78, 0x7f, 0xb4, 0x5d, 0x04, 0x26, 0x7b,
+	0x51, 0xc6, 0x7a, 0xaf, 0xf6, 0xf4, 0xe3, 0x8e, 0xdd, 0x2c, 0x17, 0xff, 0x05, 0x00, 0x00, 0xff,
+	0xff, 0x36, 0x90, 0xf4, 0x9e, 0x10, 0x06, 0x00, 0x00,
 }
diff --git a/mesh/v1alpha1/config.proto b/mesh/v1alpha1/config.proto
index 4ed253bc91..947ee9f70e 100644
--- a/mesh/v1alpha1/config.proto
+++ b/mesh/v1alpha1/config.proto
@@ -157,8 +157,13 @@ message MeshConfig {
   // will be used to generate key/cert eventually. This isn't supported for non-k8s case.
   bool enable_sds_token_mount = 23;
 
+  // The trust domain corresponds to the trust root of a system.
+  // Refer to https://github.com/spiffe/spiffe/blob/master/standards/SPIFFE-ID.md#21-trust-domain
+  // Fallback to old identity format(without trust domain) if not set.
+  string trust_domain = 26;
+
   // $hide_from_docs
-  // Next available field number: 26
+  // Next available field number: 27
 }
 
 // ConfigSource describes information about a configuration store inside a
diff --git a/mesh/v1alpha1/istio.mesh.v1alpha1.pb.html b/mesh/v1alpha1/istio.mesh.v1alpha1.pb.html
index c78edc388d..13b2d84987 100644
--- a/mesh/v1alpha1/istio.mesh.v1alpha1.pb.html
+++ b/mesh/v1alpha1/istio.mesh.v1alpha1.pb.html
@@ -263,6 +263,16 @@ <h2 id="MeshConfig">MeshConfig</h2>
 rules, and other Istio configuration artifacts. Multiple data sources
 can be configured for a single control plane.</p>
 
+</td>
+</tr>
+<tr id="MeshConfig-trust_domain">
+<td><code>trustDomain</code></td>
+<td><code>string</code></td>
+<td>
+<p>The trust domain corresponds to the trust root of a system.
+Refer to https://github.com/spiffe/spiffe/blob/master/standards/SPIFFE-ID.md#21-trust-domain
+Fallback to old identity format(without trust domain) if not set.</p>
+
 </td>
 </tr>
 </tbody>
diff --git a/proto.lock b/proto.lock
index a3e47d258d..b545da2f7d 100644
--- a/proto.lock
+++ b/proto.lock
@@ -761,6 +761,11 @@
                 "id": 23,
                 "name": "enable_sds_token_mount",
                 "type": "bool"
+              },
+              {
+                "id": 26,
+                "name": "trust_domain",
+                "type": "string"
               }
             ],
             "reserved_ids": [
diff --git a/python/istio_api/mesh/v1alpha1/config_pb2.py b/python/istio_api/mesh/v1alpha1/config_pb2.py
index 0d32c45cae..31cab13142 100644
--- a/python/istio_api/mesh/v1alpha1/config_pb2.py
+++ b/python/istio_api/mesh/v1alpha1/config_pb2.py
@@ -22,7 +22,7 @@
   name='mesh/v1alpha1/config.proto',
   package='istio.mesh.v1alpha1',
   syntax='proto3',
-  serialized_pb=_b('\n\x1amesh/v1alpha1/config.proto\x12\x13istio.mesh.v1alpha1\x1a\x1egoogle/protobuf/duration.proto\x1a\x19mesh/v1alpha1/proxy.proto\x1a*networking/v1alpha3/destination_rule.proto\"\xe0\x06\n\nMeshConfig\x12\x1a\n\x12mixer_check_server\x18\x01 \x01(\t\x12\x1b\n\x13mixer_report_server\x18\x02 \x01(\t\x12\x1d\n\x15\x64isable_policy_checks\x18\x03 \x01(\x08\x12\x1e\n\x16policy_check_fail_open\x18\x19 \x01(\x08\x12\x19\n\x11proxy_listen_port\x18\x04 \x01(\x05\x12\x17\n\x0fproxy_http_port\x18\x05 \x01(\x05\x12\x32\n\x0f\x63onnect_timeout\x18\x06 \x01(\x0b\x32\x19.google.protobuf.Duration\x12\x15\n\ringress_class\x18\x07 \x01(\t\x12\x17\n\x0fingress_service\x18\x08 \x01(\t\x12V\n\x17ingress_controller_mode\x18\t \x01(\x0e\x32\x35.istio.mesh.v1alpha1.MeshConfig.IngressControllerMode\x12\x43\n\x0b\x61uth_policy\x18\n \x01(\x0e\x32*.istio.mesh.v1alpha1.MeshConfig.AuthPolicyB\x02\x18\x01\x12\x16\n\x0e\x65nable_tracing\x18\x0c \x01(\x08\x12\x17\n\x0f\x61\x63\x63\x65ss_log_file\x18\r \x01(\t\x12\x19\n\x11\x61\x63\x63\x65ss_log_format\x18\x18 \x01(\t\x12\x38\n\x0e\x64\x65\x66\x61ult_config\x18\x0e \x01(\x0b\x32 .istio.mesh.v1alpha1.ProxyConfig\x12\'\n\x1f\x65nable_client_side_policy_check\x18\x13 \x01(\x08\x12\x14\n\x0csds_uds_path\x18\x14 \x01(\t\x12\x39\n\x0e\x63onfig_sources\x18\x16 \x03(\x0b\x32!.istio.mesh.v1alpha1.ConfigSource\x12\x1e\n\x16\x65nable_sds_token_mount\x18\x17 \x01(\x08\"9\n\x15IngressControllerMode\x12\x07\n\x03OFF\x10\x00\x12\x0b\n\x07\x44\x45\x46\x41ULT\x10\x01\x12\n\n\x06STRICT\x10\x02\"&\n\nAuthPolicy\x12\x08\n\x04NONE\x10\x00\x12\x0e\n\nMUTUAL_TLS\x10\x01J\x04\x08\x0b\x10\x0cJ\x04\x08\x0f\x10\x10J\x04\x08\x10\x10\x11J\x04\x08\x11\x10\x12J\x04\x08\x12\x10\x13J\x04\x08\x15\x10\x16\"]\n\x0c\x43onfigSource\x12\x0f\n\x07\x61\x64\x64ress\x18\x01 \x01(\t\x12<\n\x0ctls_settings\x18\x02 \x01(\x0b\x32&.istio.networking.v1alpha3.TLSSettingsB\x1cZ\x1aistio.io/api/mesh/v1alpha1b\x06proto3')
+  serialized_pb=_b('\n\x1amesh/v1alpha1/config.proto\x12\x13istio.mesh.v1alpha1\x1a\x1egoogle/protobuf/duration.proto\x1a\x19mesh/v1alpha1/proxy.proto\x1a*networking/v1alpha3/destination_rule.proto\"\xf6\x06\n\nMeshConfig\x12\x1a\n\x12mixer_check_server\x18\x01 \x01(\t\x12\x1b\n\x13mixer_report_server\x18\x02 \x01(\t\x12\x1d\n\x15\x64isable_policy_checks\x18\x03 \x01(\x08\x12\x1e\n\x16policy_check_fail_open\x18\x19 \x01(\x08\x12\x19\n\x11proxy_listen_port\x18\x04 \x01(\x05\x12\x17\n\x0fproxy_http_port\x18\x05 \x01(\x05\x12\x32\n\x0f\x63onnect_timeout\x18\x06 \x01(\x0b\x32\x19.google.protobuf.Duration\x12\x15\n\ringress_class\x18\x07 \x01(\t\x12\x17\n\x0fingress_service\x18\x08 \x01(\t\x12V\n\x17ingress_controller_mode\x18\t \x01(\x0e\x32\x35.istio.mesh.v1alpha1.MeshConfig.IngressControllerMode\x12\x43\n\x0b\x61uth_policy\x18\n \x01(\x0e\x32*.istio.mesh.v1alpha1.MeshConfig.AuthPolicyB\x02\x18\x01\x12\x16\n\x0e\x65nable_tracing\x18\x0c \x01(\x08\x12\x17\n\x0f\x61\x63\x63\x65ss_log_file\x18\r \x01(\t\x12\x19\n\x11\x61\x63\x63\x65ss_log_format\x18\x18 \x01(\t\x12\x38\n\x0e\x64\x65\x66\x61ult_config\x18\x0e \x01(\x0b\x32 .istio.mesh.v1alpha1.ProxyConfig\x12\'\n\x1f\x65nable_client_side_policy_check\x18\x13 \x01(\x08\x12\x14\n\x0csds_uds_path\x18\x14 \x01(\t\x12\x39\n\x0e\x63onfig_sources\x18\x16 \x03(\x0b\x32!.istio.mesh.v1alpha1.ConfigSource\x12\x1e\n\x16\x65nable_sds_token_mount\x18\x17 \x01(\x08\x12\x14\n\x0ctrust_domain\x18\x1a \x01(\t\"9\n\x15IngressControllerMode\x12\x07\n\x03OFF\x10\x00\x12\x0b\n\x07\x44\x45\x46\x41ULT\x10\x01\x12\n\n\x06STRICT\x10\x02\"&\n\nAuthPolicy\x12\x08\n\x04NONE\x10\x00\x12\x0e\n\nMUTUAL_TLS\x10\x01J\x04\x08\x0b\x10\x0cJ\x04\x08\x0f\x10\x10J\x04\x08\x10\x10\x11J\x04\x08\x11\x10\x12J\x04\x08\x12\x10\x13J\x04\x08\x15\x10\x16\"]\n\x0c\x43onfigSource\x12\x0f\n\x07\x61\x64\x64ress\x18\x01 \x01(\t\x12<\n\x0ctls_settings\x18\x02 \x01(\x0b\x32&.istio.networking.v1alpha3.TLSSettingsB\x1cZ\x1aistio.io/api/mesh/v1alpha1b\x06proto3')
   ,
   dependencies=[google_dot_protobuf_dot_duration__pb2.DESCRIPTOR,mesh_dot_v1alpha1_dot_proxy__pb2.DESCRIPTOR,networking_dot_v1alpha3_dot_destination__rule__pb2.DESCRIPTOR,])
 
@@ -49,8 +49,8 @@
   ],
   containing_type=None,
   options=None,
-  serialized_start=886,
-  serialized_end=943,
+  serialized_start=908,
+  serialized_end=965,
 )
 _sym_db.RegisterEnumDescriptor(_MESHCONFIG_INGRESSCONTROLLERMODE)
 
@@ -71,8 +71,8 @@
   ],
   containing_type=None,
   options=None,
-  serialized_start=945,
-  serialized_end=983,
+  serialized_start=967,
+  serialized_end=1005,
 )
 _sym_db.RegisterEnumDescriptor(_MESHCONFIG_AUTHPOLICY)
 
@@ -217,6 +217,13 @@
       message_type=None, enum_type=None, containing_type=None,
       is_extension=False, extension_scope=None,
       options=None, file=DESCRIPTOR),
+    _descriptor.FieldDescriptor(
+      name='trust_domain', full_name='istio.mesh.v1alpha1.MeshConfig.trust_domain', index=19,
+      number=26, type=9, cpp_type=9, label=1,
+      has_default_value=False, default_value=_b("").decode('utf-8'),
+      message_type=None, enum_type=None, containing_type=None,
+      is_extension=False, extension_scope=None,
+      options=None, file=DESCRIPTOR),
   ],
   extensions=[
   ],
@@ -232,7 +239,7 @@
   oneofs=[
   ],
   serialized_start=155,
-  serialized_end=1019,
+  serialized_end=1041,
 )
 
 
@@ -269,8 +276,8 @@
   extension_ranges=[],
   oneofs=[
   ],
-  serialized_start=1021,
-  serialized_end=1114,
+  serialized_start=1043,
+  serialized_end=1136,
 )
 
 _MESHCONFIG.fields_by_name['connect_timeout'].message_type = google_dot_protobuf_dot_duration__pb2._DURATION