Str.php
public static function decrypt($data, $key, $cipher = MCRYPT_RIJNDAEL_128, $mode = MCRYPT_MODE_CBC)
    {
        $key    =   hash('sha256', $key, true);

        @ list($iv, $encrypted) = (array) unserialize(base64_decode($data));

        return unserialize(trim(mcrypt_decrypt($cipher, $key, $encrypted, $mode, $iv)));
    }
public static function decrypt($data, $key, $cipher = MCRYPT_RIJNDAEL_128, $mode = MCRYPT_MODE_CBC)
    {
        $key    =   hash('sha256', $key, true);

        @ list($iv, $encrypted) = (array) unserialize(base64_decode($data));

        return unserialize(trim(mcrypt_decrypt($cipher, $key, $encrypted, $mode, $iv)));
    }
Decrypt using mcrypt

@param   mixed   $data   the data to be decrypted
@param   string  $key    the secret key
@param   string  $cipher the cipher key
@param   string  $mode   the mode
@return  string