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

``sh
npm install
npm run build
npm test
`

Install

`sh
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

`js
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.