Topic: Bustabit.com Provably Fair Seeding Event (Read 49515 times)

function genGameHash(serverSeed) {
  return crypto.createHash('sha256').update(serverSeed).digest('hex');
}

function crashPointFromHash(serverSeed, clientSeed) {
  function divisible(hash, mod) {
    // We will read in 4 hex at a time, but the first chunk might be a bit smaller
    // So ABCDEFGHIJ should be chunked like  AB CDEF GHIJ
    var val = 0;
    
    var o = hash.length % 4; 
    for (var i = o > 0 ? o - 4 : 0; i < hash.length; i += 4) {
      val = ((val << 16) + parseInt(hash.substring(i, i+4), 16)) % mod;
    }

    return val === 0;
  }

  var hash = crypto.createHmac('sha256', serverSeed).update(clientSeed).digest('hex');

  /* In 1 of 101 games the game crashes instantly. */
  if (divisible(hash, 101))
     return 0;

  /* Use the most significant 52-bit from the hash
     to calculate the crash point */
  var h = parseInt(hash.slice(0,52/4),16);
  var e = Math.pow(2,52);

  return Math.floor((100 * e - h) / (e - h));
}

var serverSecret =  'If you knew this, you could steal all my money';
var clientSeed = '0000examplehash';

var gamesToGenerate = 1e7;

var serverSeed = serverSecret;

for (var game = gamesToGenerate; game > 0; --game) {
  serverSeed = genGameHash(serverSeed);
  console.log('Game ' +  game + ' has a crash point of ' + (crashPointFromHash(serverSeed, clientSeed) / 100).toFixed(2) +'x', '\t\tHash: ' + serverSeed);
}

var terminatingHash = genGameHash(serverSeed);

console.log('The terminating hash is: ', terminatingHash);

function genGameHash(serverSeed) {
  return crypto.createHash('sha256').update(serverSeed).digest('hex');
}

function crashPointFromHash(serverSeed, clientSeed) {
  function divisible(hash, mod) {
    // We will read in 4 hex at a time, but the first chunk might be a bit smaller
    // So ABCDEFGHIJ should be chunked like  AB CDEF GHIJ
    var val = 0;
    
    var o = hash.length % 4; 
    for (var i = o > 0 ? o - 4 : 0; i < hash.length; i += 4) {
      val = ((val << 16) + parseInt(hash.substring(i, i+4), 16)) % mod;
    }

    return val === 0;
  }

  var hash = crypto.createHmac('sha256', serverSeed).update(clientSeed).digest('hex');

  /* In 1 of 101 games the game crashes instantly. */
  if (divisible(hash, 101))
     return 0;

  /* Use the most significant 52-bit from the hash
     to calculate the crash point */
  var h = parseInt(hash.slice(0,52/4),16);
  var e = Math.pow(2,52);

  return Math.floor((100 * e - h) / (e - h));
}

var serverSecret =  'If you knew this, you could steal all my money';
var clientSeed = '0000examplehash';

var gamesToGenerate = 1e7;

var serverSeed = serverSecret;

for (var game = gamesToGenerate; game > 0; --game) {
  serverSeed = genGameHash(serverSeed);
  console.log('Game ' +  game + ' has a crash point of ' + (crashPointFromHash(serverSeed, clientSeed) / 100).toFixed(2) +'x', '\t\tHash: ' + serverSeed);
}

var serverSeed = 'If you knew this, you could steal all my money'; // example
var clientSeed = '000000000000000012e8c0efdff2b8f67282e211749cc5530bd6e709f70279e1'; // determined by this seeding event

var gamesToGenerate = 100; // It'll be much larger in reality

for (var game = gamesToGenerate; game > 0; --game) {
  serverSeed = genGameHash(serverSeed, clientSeed);
  console.log('Game ' +  game + ' has a crash point of ' + (crashPointFromHash(serverSeed) / 100).toFixed(2) +'x', '\t\tHash: ' + serverSeed);
}

function genGameHash(serverSeed, clientSeed) {
  return crypto.createHmac('sha256', serverSeed).update(clientSeed).digest('hex');
}

function crashPointFromHash(hash) {
  // Returns an integers corresponding to the game crash. 123 = Game crashes at 1.23x

  function divisible(hash, mod) {
    // We will read in 4 hex at a time, but the first chunk might be a bit smaller
    // So ABCDEFGHIJ should be chunked like  AB CDEF GHIJ
    var val = 0;
    
    var o = hash.length % 4; 
    for (var i = o > 0 ? o - inc : 0; i < hash.length; i += 4) {
      val = ((val << 16) + parseInt(hash.substring(i, i+4), 16)) % mod;
    }

    return val === 0;
  }

  /* In 1 of 101 games the game crashes instantly. */
  if (divisible(hash, 101))
    return 0;

  /* Use the most significant 52-bit from the hash
     to calculate the crash point */
  var h = parseInt(hash.slice(0,52/4),16);
  var e = Math.pow(2,52);

  /* Assuming the 52-bit prefix is uniformly distributed
     then r is uniformly distributed over [0,1). */
  var r = h / e;

  /* Perfect is the perfectly continuous distributed
     multiplier for a zero sum game. */
  var perfect    = 1 / (1 - r);

  /* Apply a house edge to the perfect distribution. */
  var houseEdge  = (perfect-1) * 0.01;
  var multiplier = perfect - houseEdge;

  // return Math.floor(multiplier * 100);

  /* Inlining and simplifying the above yields the following version
     which is slightly more numerically stable. The multiplication
     100 * e still leaves the exactly representable integers.
  */
  return Math.floor((100 * e - h) / (e - h));
}

var serverSeed = 'If you knew this, you could steal all my money'; // example
var clientSeed = '000000000000000012e8c0efdff2b8f67282e211749cc5530bd6e709f70279e1'; // determined by this seeding event

var gamesToGenerate = 100; // It'll be much larger in reality

for (var game = gamesToGenerate; game > 0; --game) {
  serverSeed = genGameHash(serverSeed, clientSeed);
  console.log('Game ' +  game + ' has a crash point of ' + (crashPointFromHash(serverSeed) / 100).toFixed(2) +'x', '\t\tHash: ' + serverSeed);
}