https://github.com/andykswong/pfrng

Provably Fair Random Number Generator
https://github.com/andykswong/pfrng

javascript nodejs provably-fair random typescript

Last synced: 8 days ago
JSON representation

Provably Fair Random Number Generator

• Host: GitHub
• URL: https://github.com/andykswong/pfrng
• Owner: andykswong
• License: mit
• Created: 2021-03-14T07:49:45.000Z (over 3 years ago)
• Default Branch: main
• Last Pushed: 2023-05-25T00:49:33.000Z (over 1 year ago)
• Last Synced: 2024-11-03T02:02:38.316Z (12 days ago)
• Topics: javascript, nodejs, provably-fair, random, typescript
• Language: TypeScript
• Homepage: https://andykswong.github.io/pfrng/
• Size: 372 KB
• Stars: 6
• Watchers: 2
• Forks: 5
• Open Issues: 1
• Metadata Files:
  • Readme: README.md
  • License: LICENSE

Awesome Lists containing this project

README

        
# pfrng - Provably Fair Random Number Generator

[![NPM](https://img.shields.io/npm/v/pfrng)](https://www.npmjs.com/package/pfrng) [![build](https://github.com/andykswong/pfrng/actions/workflows/build.yaml/badge.svg)](https://github.com/andykswong/pfrng/actions/workflows/build.yaml)

> A library of [provably fair](https://en.wikipedia.org/wiki/Provably_fair_algorithm) random number generators, distributions and helpers.

## Install

```shell

npm install pfrng

```

## Usage

Example provably fair coin flipping game:

```js

import {

  bitIter, CoinSide, commitment, flipCoin, keyedMessage, 

  nodeCryptoRandomBytes, nodeHash, randomBytesFromHash, sha512Iter

} from '.';

// 1. Server generates a seed and send serverCommitment to client

const serverRandomIter = sha512Iter(nodeCryptoRandomBytes());

const serverSeed = serverRandomIter.next().value;

const serverCommitment = commitment(nodeHash.sha3_512, serverSeed);

// 2. Client generates a seed and places a bet

const clientRandomIter = sha512Iter(nodeCryptoRandomBytes());

const clientSeed = clientRandomIter.next().value;

const clientNumHeadsBet = 3;

// 3. Server seeds the random generators with client + server seeds

const randomBytes = randomBytesFromHash(nodeHash.sha3_512, keyedMessage(clientSeed, serverSeed));

const randomBits = bitIter(randomBytes);

// 4. Server simulates the game

let isWinning = true;

for (let i = 0; i < clientNumHeadsBet; ++i) {

  const isHead = flipCoin(randomBits) === CoinSide.Head;

  isWinning = isWinning && isHead;

  console.log(`Coin flip ${i}: ${isHead ? 'head' : 'tail'}`);

}

console.log(`You ${isWinning ? 'win' : 'lose'}.`);

// 5. Server reveals serverSeed to client for verification

```

## API

TSDoc: http://andykswong.github.io/pfrng

## License

This repository and the code inside it is licensed under the MIT License. Read [LICENSE](./LICENSE) for more information.