ID混淆算法

<?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;}}