Mcrypt

Mcrypt supports a wide variety of block algorithms such as DES, TripleDES, Blowfish (default), 3-WAY, SAFER-SK64, SAFER-SK128, TWOFISH, TEA, RC2 and GOST in CBC, OFB, CFB and ECB cipher modes. Additionally, it supports RC6 and IDEA.

For more information on mcrypt, check us2.php.net/manual/en/ref.mcrypt.php.