Latest posts of: apaktomy

Quote from: BC.GAME on June 19, 2020, 05:45:30 AM

Hello world,

Based on community feedback, we're currently in the process of upgrading the Crash game algorithm with salting as requested. The purpose of this post is to describe the new changes within the game result algorithm in addition to publicizing our reseeding event for Crash. Below are the differences in how the game results are generated:

OLD GAME RESULT FORMULA

Code:


  const gameResult = (seed) => {
    const nBits = 52; // number of most significant bits to use
    // 1. r = 52 most significant bits
    seed = seed.slice(0, nBits / 4);
    const r = parseInt(seed, 16);
    // 2. X = r / 2^52
    let X = r / Math.pow(2, nBits); // uniformly distributed in [0; 1)
    X = parseFloat(X.toPrecision(9));
    // 3. X = 99 / (1-X)
    X = 99 / (1 - X);
    // 4. return max(trunc(X), 100)
    const result = Math.floor(X);
    return Math.max(1, result / 100);
  };

NEW GAME RESULT FORMULA

Code:


  const gameResult = (seed, salt) => {
    const nBits = 52; // number of most significant bits to use

    // 1. HMAC_SHA256(message=seed, key=salt)  
    const hmac = CryptoJS.HmacSHA256(CryptoJS.enc.Hex.parse(seed), salt);
    seed = hmac.toString(CryptoJS.enc.Hex);

    // 2. r = 52 most significant bits
    seed = seed.slice(0, nBits / 4);
    const r = parseInt(seed, 16);

    // 3. X = r / 2^52
    let X = r / Math.pow(2, nBits); // uniformly distributed in [0; 1)
    X = parseFloat(X.toPrecision(9));

    // 4. X = 99 / (1-X)
    X = 99 / (1 - X);

    // 5. return max(trunc(X), 100)
    const result = Math.floor(X);
    return Math.max(1, result / 100);
  };

Prior to being used for calculation, each game hash is salted with the lowercase + hexadecimal string representation of the hash from pre-selected Bitcoin block 635,380. This block has not been mined yet as of this post, proving that we have not deliberately selected a mined block with a hash that could be favorable to the house. Once block 635,380 has been mined, the results will be posted to this thread as a reply. The game this post is referencing is at https://bc.game/crash.