Syntax:
ENCODE(str,pass_str)

Encrypt str using pass_str as the password. To decrypt the result, use
DECODE().

The result is a binary string of the same length as str.

The strength of the encryption is based on how good the random
generator is. It should suffice for short strings.

URL: http://dev.mysql.com/doc/refman/5.1/en/encryption-functions.html

