... 3.0.8 - 3.0.18 only, PHP 4 >= 4.0.0) mcrypt_cbc -- Encrypt/decrypt data in CBC mode . string mcrypt_cbc ( int cipher, string key, string data, int mode [, string iv])string mcrypt_cbc ( string cipher, string key, string data, int mode [, string iv]) . The first prototype is when linked against libmcrypt 2.2.x, the second when linked against libmcrypt 2.4.x. mcrypt_cbc() encrypts or decrypts (depending on mode ) the data with cipher and key in CBC cipher mode and returns the resulting string. ...