crypto-keygen-suite/keyGen/shamir/distributeShares.js

Key generation utilities for cryptographic operations. YES I RENAMED IT. SIX STATE PROTOCOL!!! See its folder for all <3

import { program } from 'commander';

// Function to generate a random polynomial of given degree with the secret as the constant term
function generatePolynomial(degree, secret) {
    const coefficients = Array.from({ length: degree }, () => Math.floor(Math.random() * 256));
    coefficients.push(secret); // The secret is the constant term
    return coefficients;
}

// Function to evaluate the polynomial at a given x value
function evaluatePolynomial(coefficients, x) {
    return coefficients.reduce((acc, coeff, index) => {
        return (acc + coeff * Math.pow(x, index)) % 256; // Modulo 256 for simplicity
    }, 0);
}

// Function to distribute shares among parties
function distributeShares(secret, totalShares, threshold) {
    const polynomial = generatePolynomial(threshold - 1, secret);
    const shares = [];

    for (let i = 1; i <= totalShares; i++) {
        const shareValue = evaluatePolynomial(polynomial, i);
        shares.push({ index: i, share: shareValue });
    }

    return shares;
}

// Main function to handle command-line arguments
function main() {
    program
        .requiredOption('--secret <number>', 'The secret to be shared')
        .requiredOption('--totalShares <number>', 'Total number of shares to create')
        .requiredOption('--threshold <number>', 'Minimum number of shares needed to reconstruct the secret')
        .parse(process.argv);

    const options = program.opts();
    const secret = parseInt(options.secret, 10);
    const totalShares = parseInt(options.totalShares, 10);
    const threshold = parseInt(options.threshold, 10);

    const shares = distributeShares(secret, totalShares, threshold);
    console.log("Distributed Shares:", shares);
}

main();