PHP实现的ID混淆算法类与用法示例

<?php/** * ID混淆算法 */class IdCrypt{  /**   * 对整数id进行可逆混淆   */  public static function encodeId($id)  {    $sid = ($id & 0xff000000);    $sid += ($id & 0x0000ff00) << 8;    $sid += ($id & 0x00ff0000) >> 8;    $sid += ($id & 0x0000000f) << 4;    $sid += ($id & 0x000000f0) >> 4;    $sid ^= 11184810;    return $sid;  }  /**   * 对通过encodeId混淆的id进行还原   */  public static function decodeId($sid)  {    if (!is_numeric($sid)) {      return false;    }    $sid ^= 11184810;    $id = ($sid & 0xff000000);    $id += ($sid & 0x00ff0000) >> 8;    $id += ($sid & 0x0000ff00) << 8;    $id += ($sid & 0x000000f0) >> 4;    $id += ($sid & 0x0000000f) << 4;    return $id;  }}$idstr = new IdCrypt();echo $encodeid = $idstr->encodeId('12345678');echo "<br/>";echo $decodeid = $idstr->decodeId($encodeid);?>