qct / gnark

gnark is a fast zk-SNARK library that offers a high-level API to design circuits. The library is open source and developed under the Apache 2.0 license

gnark zk-SNARK library

gnark is a fast zk-SNARK library that offers a high-level API to design circuits. The library is open source and developed under the Apache 2.0 license

Useful Links

• gnark User Documentation
• gnark Playground
• gnark Issues
• gnark Benchmarks 🏁
• gnark-announce - Announcement list for new releases and security patches

gnark Users

To get started with gnark and write your first circuit, follow these instructions.

Checkout the online playground to compile circuits and visualize constraint systems.

Warning

gnark has been partially audited and is provided as-is, we make no guarantees or warranties to its safety and reliability. In particular, gnark makes no security guarantees such as constant time implementation or side-channel attack resistance.

gnark and gnark-crypto packages are optimized for 64bits architectures (x86 amd64) and tested on Unix (Linux / macOS).

Issues

gnark issues are tracked in the GitHub issues tab.

To report a security bug, please refer to gnark Security Policy.

If you have any questions, queries or comments, GitHub discussions is the place to find us.

You can also get in touch directly: [e-mail]

Release Notes

Release Notes

Proving schemes and curves

Refer to Proving schemes and curves for more details.

gnark support the following zk-SNARKs:

• Groth16
• PlonK

which can be instantiated with the following curves

• BN254
• BLS12-381
• BLS12-377
• BW6-761
• BLS24-315
• BW6-633
• BLS24-317

Example

Refer to the gnark User Documentation

Here is what x**3 + x + 5 = y looks like

package main

import (
	"github.com/consensys/gnark-crypto/ecc"
	"github.com/consensys/gnark/backend/groth16"
	"github.com/consensys/gnark/frontend"
	"github.com/consensys/gnark/frontend/cs/r1cs"
)

// CubicCircuit defines a simple circuit
// x**3 + x + 5 == y
type CubicCircuit struct {
	// struct tags on a variable is optional
	// default uses variable name and secret visibility.
	X frontend.Variable `gnark:"x"`
	Y frontend.Variable `gnark:",public"`
}

// Define declares the circuit constraints
// x**3 + x + 5 == y
func (circuit *CubicCircuit) Define(api frontend.API) error {
	x3 := api.Mul(circuit.X, circuit.X, circuit.X)
	api.AssertIsEqual(circuit.Y, api.Add(x3, circuit.X, 5))
	return nil
}

func main() {
	// compiles our circuit into a R1CS
	var circuit CubicCircuit
	ccs, _ := frontend.Compile(ecc.BN254.ScalarField(), r1cs.NewBuilder, &circuit)

	// groth16 zkSNARK: Setup
	pk, vk, _ := groth16.Setup(ccs)

	// witness definition
	assignment := CubicCircuit{X: 3, Y: 35}
	witness, _ := frontend.NewWitness(&assignment, ecc.BN254.ScalarField())
	publicWitness, _ := witness.Public()

	// groth16: Prove & Verify
	proof, _ := groth16.Prove(ccs, pk, witness)
	groth16.Verify(proof, vk, publicWitness)
}

Citing

If you use gnark in your research a citation would be appreciated. Please use the following BibTeX to cite the most recent release.

@software{gnark-v0.8.0,
  author       = {Gautam Botrel and
                  Thomas Piellard and
                  Youssef El Housni and
                  Ivo Kubjas and
                  Arya Tabaie},
  title        = {ConsenSys/gnark: v0.8.0},
  month        = feb,
  year         = 2023,
  publisher    = {Zenodo},
  version      = {v0.8.0},
  doi          = {10.5281/zenodo.5819104},
  url          = {https://doi.org/10.5281/zenodo.5819104}
}

Contributing

Please read CONTRIBUTING.md for details on our code of conduct, and the process for submitting pull requests to us.

Versioning

We use SemVer for versioning. For the versions available, see the tags on this repository.

License

This project is licensed under the Apache 2 License - see the LICENSE file for details