go-snark

go-snark

Go implementation of the Groth16 protocol zkSNARK prover & verifier compatible with:

• circom (WIP)
• bellman (TODO)

Using bn256 (used by go-ethereum) for the Pairing curve operations.

Usage

• Generate Proof

import (
  "github.com/vocdoni/go-snark/parsers"
  "github.com/vocdoni/go-snark/prover"
  "github.com/vocdoni/go-snark/verifier"
)

[...]

// read ProvingKey & Witness files
provingKeyJSON, _ := ioutil.ReadFile("../testdata/circuit1k/proving_key.json")
witnessJSON, _ := ioutil.ReadFile("../testdata/circuit1k/witness.json")

// parse Proving Key
pk, _ := parsers.ParsePk(provingKeyJSON)

// parse Witness
w, _ := parsers.ParseWitness(witnessJSON)

// generate the proof
proof, pubSignals, _ := prover.GenerateProof(pk, w)

// print proof & publicSignals
proofStr, _ := parsers.ProofToJSON(proof)
publicStr, _ := json.Marshal(parsers.ArrayBigIntToString(pubSignals))
fmt.Println(proofStr)
fmt.Println(publicStr)

• Verify Proof

// read proof & verificationKey & publicSignals
proofJSON, _ := ioutil.ReadFile("../testdata/circuit1k/proof.json")
vkJSON, _ := ioutil.ReadFile("../testdata/circuit1k/verification_key.json")
publicJSON, _ := ioutil.ReadFile("../testdata/circuit1k/public.json")

// parse proof & verificationKey & publicSignals
public, _ := parsers.ParsePublicSignals(publicJSON)
proof, _ := parsers.ParseProof(proofJSON)
vk, _ := parsers.ParseVk(vkJSON)

// verify the proof with the given verificationKey & publicSignals
v := verifier.Verify(vk, proof, public)
fmt.Println(v)

CLI

From the cli directory:

• Show options

> go run cli.go -help
go-snark
                 v0.0.1
Usage of go-snark:
  -proof string
        proof path (default "proof.json")
  -prove
        prover mode
  -provingkey string
        provingKey path (default "proving_key.json")
  -public string
        public signals path (default "public.json")
  -verificationkey string
        verificationKey path (default "verification_key.json")
  -verify
        verifier mode
  -witness string
        witness path (default "witness.json")

• Prove

> go run cli.go -prove -provingkey=../testdata/circuit5k/proving_key.json -witness=../testdata/circuit5k/witness.json

• Verify

> go run cli.go -verify -verificationkey=../testdata/circuit5k/verification_key.json