npvdkgrs

Non-interactive publicly verifiable distributed key generation and resharing algorithm over BLS12-381

Overview

This library implements a non-interactive publicly verifiable distributed key generation (DKG) and key resharing protocol using the BLS12-381 pairing-friendly elliptic curve. It is built using the Arkworks library for elliptic curve cryptography.

The protocol allows a group of participants to jointly generate a shared public key and corresponding private key shares, without requiring interactive communication rounds. It also supports resharing to change the set of participants or threshold.

Key features:

• Non-interactive DKG and resharing
• Publicly verifiable
• Secure against malicious adversaries
• Built on Arkworks & round-based model
• DKG is just one round
• Resharing is just one round
• Signing is just one round and is non-interactive
• Asynchronous API

Installation

Add this to your Cargo.toml:

[dependencies]
npvdkgrs = "0.1.0"

Usage

Key Generation

use ark_std::UniformRand;
use npvdkgrs::{keygen, party::KeysharePackage, Keypair, PublicKey};

async fn run_dkg(participants: &[PublicKey], threshold: u16) -> Result<KeysharePackage, Error> {
    let mut rng = rand::thread_rng();
    let my_keypair = Keypair::rand(&mut rng);
    let tracer = None;

    let pkg = keygen::run(
        &mut rng,
        tracer,
        &my_keypair,
        participants,
        threshold,
        party
    ).await?;

    Ok(pkg)
}

Signing

use npvdkgrs::{sign, Signature};

async fn sign_message(
    keypair: &Keypair,
    pkg: &KeysharePackage,
    participants: &[PublicKey],
    message: &[u8],
) -> Result<Signature, Error> {
    let sig = sign::run(
        None,
        keypair,
        pkg,
        participants,
        message,
        party
    ).await?;

    Ok(sig)
}

Verification

use npvdkgrs::Signature;

fn verify_signature(signature: &Signature, message: &[u8], public_key: &PublicKey) -> bool {
    signature.verify(message, public_key)
}

Features

• std: Use the Rust standard library (enabled by default)
• parallel: Enable parallel computation optimizations using Rayon
• asm: Use assembly optimizations for improved performance
• print-trace: Print debug traces for development and troubleshooting
• getrandom: Enable getrandom feature for secure random number generation
• state-machine: Enable state machine for round-based protocols

Security Assumptions

The security of this protocol relies on the following assumptions:

1. The hardness of the Discrete Logarithm problem in BLS12-381.
2. The Random Oracle Model for hash functions.
3. The honesty of at least t+1 participants, where t is the threshold.

For more details on the security proofs and assumptions, please refer to the NPVDKGRS paper.

Performance

Benchmarks for different participant counts and thresholds:

Note: These benchmarks were run on a machine with M1 Macbook PRO. Your results may vary, see benches dir

Contributing

Contributions are welcome! Please feel free to submit a Pull Request.

1. Fork the repository
2. Create your feature branch (git checkout -b my-new-feature)
3. Commit your changes (git commit -am 'Add some feature')
4. Push to the branch (git push origin my-new-feature)
5. Create a new Pull Request

Please make sure to update tests as appropriate and adhere to the existing coding style.

Reporting Issues

If you find a bug or have a feature request, please open an issue on GitHub.

License

This project is licensed under either of

• Apache License, Version 2.0, (LICENSE-APACHE or http://www.apache.org/licenses/LICENSE-2.0)
• MIT license (LICENSE-MIT or http://opensource.org/licenses/MIT)

at your option.

References

The protocol is based on the paper:

NPVDKGRS: Non-Interactive Publicly Verifiable Distributed Key Generation and Resharing over BLS12-381

Acknowledgements

This project makes use of the following libraries:

• Arkworks
• round-based

We thank the authors and contributors of these projects for their valuable work.