cggmp-node-binding

Node.js native binding for CGGMP24 MPC ECDSA protocol - Distributed key generation and threshold signing without exposing private keys.

Based on cggmp21 Rust implementation.

Features

• Distributed Key Generation (DKG): Generate ECDSA key shares across multiple parties
• Threshold Signing: Sign messages with a subset of parties (t-of-n)
• Auxiliary Info Generation: Generate pre-computation data for efficient signing
• State Machine API: Round-based protocol execution with CggmpExecutor
• Cross-platform: Pre-built binaries for macOS, Linux, and Windows

Installation

npm install @kshan0515/cggmp-node-binding
# or
pnpm add @kshan0515/cggmp-node-binding
# or
yarn add @kshan0515/cggmp-node-binding

Supported Platforms

| Platform | Architecture | |----------|-------------| | macOS | x64, arm64 (Apple Silicon) | | Linux | x64 (glibc, musl), arm64 (glibc) | | Windows | x64 |

Usage

import { CggmpExecutor, generatePrimes } from '@kshan0515/cggmp-node-binding';

// Create executor for party 0 in a 2-of-3 threshold setup
const executor = new CggmpExecutor(
  'session-id',
  'execution-id',
  0,  // party index
  2,  // threshold
  3   // total parties
);

// Start auxiliary info generation
executor.startAuxGen();

// Process protocol rounds
const outgoing = executor.step([]);
// ... exchange messages with other parties ...

// Check status
const snapshot = JSON.parse(executor.snapshot());
console.log(snapshot.status);

// After aux gen, start keygen
executor.startKeygen();
// ... continue processing rounds ...

// After keygen, export key share
const keyShare = executor.exportKeyshare();

// For signing, import key share and start signing
executor.importKeyshare(keyShare);
executor.setSigners('[0, 1]');  // Select signers
executor.startSigning('0x...');  // Message hash (32 bytes hex)

API

CggmpExecutor

Main class for MPC protocol execution.

Constructor

new CggmpExecutor(
  sessionId: string,
  executionId: string,
  partyIndex: number,
  threshold: number,
  partiesCount: number
)

Methods

| Method | Description | |--------|-------------| | startAuxGen() | Start auxiliary info generation | | startAuxGenWithPrimes(primes: Buffer) | Start aux gen with pre-generated primes | | startKeygen() | Start distributed key generation | | startSigning(txHex: string) | Start signing (32-byte hash as hex) | | step(inputs: Buffer[]): Buffer[] | Process incoming messages and return outgoing | | snapshot(): string | Get current state as JSON | | setSigners(json: string) | Set signer indices for signing | | importKeyshare(data: Buffer) | Import key share | | exportKeyshare(): Buffer | Export key share | | importAuxInfo(data: Buffer) | Import auxiliary info | | exportAuxInfo(): Buffer | Export auxiliary info |

generatePrimes(): Buffer

Pre-generate safe primes for faster auxiliary info generation.

Protocol Flow

1. Auxiliary Info Generation: Generate Paillier keys and ring-Pedersen parameters
2. Key Generation: Generate ECDSA key shares using VSS
3. Signing: Create threshold signatures with selected signers

Building from Source

Requirements:

• Node.js >= 18
• Rust (stable)
• pnpm

# Install dependencies
pnpm install

# Build native binary
pnpm build

# Run tests
pnpm test

Security

This library implements the CGGMP24 protocol which provides:

• UC-secure key generation
• Identifiable abort in case of malicious behavior
• Threshold security (t-of-n)

Warning: This is a cryptographic library. Use with caution in production environments.

License

MIT

References

• CGGMP24 Paper
• cggmp21 Rust Implementation