Provably Fair Framework

This library aims to provide a flexible but thorough provably fair framework.

Hash Algorithms

Accepted Hash Algorithms are sha256 and sha512. Default is sha256.

Random Algorithms

Random Integer

randomInteger(algorithm, inputs, min, max)

Random Sequence (Fisher–Yates shuffle)

randomSequence(algorithm, inputs, array)

Strategies

• Crash
• Dice
• American Roulette
• European Roulette

Usage

import {
  Algorithm,
  AmericanRoulette,
  Config,
  Crash,
  createSystem,
  Dice,
  distribute,
  EuropeanRoulette,
  randomInteger,
  randomSequence,
  System
} from "provably-fair-framework";

// Default config
const config: Config = {
  algorithm: "sha256",
  proofOfCommitment() {
    log("Custom proof of commitment..");
  },
  proofOfExistence() {
    log("Custom proof of existence...");
  },
  seedingEvent() {
    log("Custom seeding event...");
  },
  strategies: [AmericanRoulette, Crash, Dice, EuropeanRoulette],
  strategy: Dice
};

const system = createSystem(config);

const [serverSeed, clientSeed] = await system.createSeedPair();

// A dice strategy
system.setStrategy(Dice);
const dice = system.calculate(serverSeed, clientSeed);
console.log(dice); // 1-6

// A european roulette example
system.setStrategy(EuropeanRoulette);
const roulette = system.calculate(serverSeed, clientSeed);
console.log(roulette); // 0-36

// A custom roulette example
import { StrategyInterface, randomInteger } from "provably-fair-system";
class CustomRoulette implements StrategyInterface {
  calculate(algorithm: Algorithm, inputs: [string, string]) {
    return randomInteger(algorithm, inputs, 0, 15);
  }
}
// Set custom strategy programatically
system.setStrategy(new CustomRouletteStrategy());

const roulette = system.calculate(serverSeed, clientSeed);
console.log(roulette); // 0-15

// default seeding event
system.seedingEvent();

// Set custom seeding event programatically
system.setSeedingEvent(new CustomSeedingEvent());
system.seedingEvent();

// default proof of existence
system.proofOfExistence();

// Set custom proof of existence programatically
system.setProofOfExistence(new CustomProofOfExistance());
system.proofOfExistence();

// default proof of commitment
system.proofOfCommitment();

// Set custom proof of commitment programatically
system.setProofOfCommitment(new CustomProofOfCommitment());
system.proofOfCommitment();

Exampes

git clone https://github.com/matthewlilley/provably-fair-framework.git

cd provably-fair-framework

npm install

npm run examples ./examples/calculate.ts

Seeding Event (Optional)

"A provably fair seeding event makes it possible to generate publicSeed using a trustless randomization service (e.g. the hash of a specific upcoming block in the blockchain of a cryptocurrency), disallowing participants to have a direct influence on in-game randomization"

You can optionally use a seeding event to generate a public seed, a seeding event generally consists of two functions, Proof of Commitment and Proof of Existence.

You can set your own custom Seeding Event Strategy, a default one is included.

Proof of Commitment

The default proof of commitment strategy is as follows:

Take an initial Server Seed (it could be a private key of Bitcoin wallet) and recusively sha256 hash it 10,000,000 times.

You can set your own custom Proof of Commitment strategy.

Proof of Existence

The default proof of existence strategy is as follows:

Broadcast via the Blockstream Satellite API a message containing the Terminating Hash, and chosen Block Height of future block. The blockhash of this will be used as a client seed.

You can set your own custom Proof of Existence strategy.

Docs

https://matthewlilley.github.io/provably-fair-framework/

Contributing

Want to contribute? Awesome! Feel free to create an issue and/or pull request.

Licence

MIT