mpc-crypto-lib

This library provides data encryption functionalities for multi-party computation (MPC). Its primary purpose is to input a row of data, perform arithmetic secret sharing, and then hybrid encrypt (RFC-9180) the shares of each node with their respective public keys. Finally, all the encrypted shares are outputted as a single-string cipher.

This Typescript module works in both web browsers and Node.js.

Run Tests

npm install
npm run build
npm test

Install

npm i mpc-crypto-lib

Cell Types

Type	Supported	Description
number	Yes	All numbers, both decimals and integers, are converted to a fixed-point BigInt representation.
string	Yes	Strings are hashed to non-cryptographically collision-resistant 64-bit BigInts. It will, therefore, only support equal comparisons.
boolean	Yes	Represented as BigInt(0) for false, and BigInt(1) for true.

Example

import {
  toBigIntRow,
  secretShareAndEncrypt,
  generateKeyPair,
  decryptOneParty,
  defaultPrime,
} from "mpc-crypto-lib";

async function demo() {
  // Generate key pair for MPC node 1
  const kp1 = await generateKeyPair();

  // Generate key pair for MPC node 1
  const kp2 = await generateKeyPair();

  // Input data
  const orignalRow = { a: "abc", b: true, c: 12.3 };

  // Convert cells to BigInt
  const mpcRow = await toBigIntRow(orignalRow);

  // Encrypt row with MPC public keys
  const cipher = await secretShareAndEncrypt(mpcRow, [
    kp1.publicKey,
    kp2.publicKey,
  ]);

  // MPC node 1 decrypts its secret shares
  const row1 = await decryptOneParty(cipher, kp1.privateKey, kp1.publicKey);

  // MPC node 2 decrypts its secret shares
  const row2 = await decryptOneParty(cipher, kp2.privateKey, kp2.publicKey);

  console.log((row1.a + row2.a) % defaultPrime === mpcRow.a); // true
}

demo();

Acknowledgment

This project was supported by the National Science Foundation under grant #2026461.