可证明公平的游戏 | VRF验证与透明随机数生成

什么是可证明公平？

可证明公平意味着每场游戏的结果都是由玩家可以独立验证的随机值生成的。这保证了透明度和公平性，确保玩家和娱乐城都无法操纵结果。

如何运作？

VRF（可验证随机函数）为了生成真正的随机值，我们使用VRF。此函数接受多个输入，包括用户ID、游戏名称、游戏随机数和娱乐城的密钥。它执行加密计算并输出随机值和证明。此证明允许任何人验证该值是公平生成的且未被篡改。我们遵循RFC6979 VRF实现，使用SECP256K1_SHA256_TAI密码套件以实现安全和可验证的随机性。

验证公平性

玩家可以使用以下代码独立验证随机值：

const { verify } = require('@roamin/ecvrf')
const toHex = require('string-hex')

const publicKey = '03c41192ba26b7efafa9c69c941f759690d4fd46761c8424edbad1d5fc2c5c0947'
const request = 'e1bc2c47-9b42-4409-8a21-d4c4f46455be|rollbit:mines|25|1234costam'
const random = 'e2983665217b5aaebf11c886ef31e001c9615362b0aa6c3e49de9057f8979e1d'
const proof = '03008cd333b153dddcffc64abf357222d31cd6e6f85ddbbe9227a60d2d0edcf9e6ab0f088c1f4402e6b4fa0ef430612d3ca86a686fc857ff412a8fe1553c821f47fcc21f4b2ca1d4c3b09b59a7e4fe1b8a'

try {
  const result = verify(publicKey, proof, toHex(request))
  console.log(result === random ? 'Is Verified' : 'Not Verified')
} catch (error) {
  console.log(error)
}

计算游戏结果

一旦验证，随机值将转换为数字：

import * as crypto from 'crypto';
function bytesToUniformFloat(xs) {
    const hash = crypto.createHash('blake2b512').update(xs).digest();
    const value = hash.readBigUInt64LE(0);
    return Number(value) / Number(BigInt(2 ** 64 - 1));
  }

然后使用此转换后的数字根据游戏特定逻辑生成最终游戏结果。

function calcMinesIxs({ size, mines, randomValue }) {
  const remainingIxs = Array.from({ length: size }, (_, i) => i);
  const mineIxs = [];
  for (let i = 0; i < mines; i++) {
    const seedI = Buffer.from(randomValue + '-' + i, 'ascii');
    const ixI = Math.floor(bytesToUniformFloat(seedI) * remainingIxs.length);
    mineIxs.push(remainingIxs[ixI]);
    remainingIxs.splice(ixI, 1);
  }
  return mineIxs;
}

const calcMinesWin = ({ size, mines, reveals, bet }) => {
  let mult = 1.0;
  for (let i = 0; i < reveals; i++) {
    const lossProbability = mines / (size - i);
    mult *= 1.0 / (1.0 - lossProbability);
  }
  return Math.floor(100.0 * bet * mult * 0.98) / 100.0;
};

function generateBoard({ size, mines, randomValue }) {
  const mineIxs = calcMinesIxs({ size, mines, randomValue });
  const sizeSqrt = Math.sqrt(size);
  const board = Array.from({ length: sizeSqrt }).map(() => Array(sizeSqrt).fill(0));
  for (const index of mineIxs) {
    const row = Math.floor(index / sizeSqrt);
    const col = index % sizeSqrt;
    if (row < sizeSqrt && col < sizeSqrt) {
      board[row][col] = -1;
    }
  }
  console.log('Board:', board);
  return board;
}

generateBoard({ size: 25, mines: 2, randomValue: 'be87e890f696aad0aad28bef78a3f2322c7687a76ff6f86b6dadb4f2aa00eeb9' });
console.log('Multipliers:');
for (let i = 1; i < 24; i++) {
  console.log(i, ': ', calcMinesWin({ size: 25, mines: 2, reveals: i, bet: 1 }));
}