The mechanism employed by crypt() is a one-way encryption. It is
intended for verifying a known value like a password. The supplied
value is encrypted and compared to the stored, encrypted value, and if
they match, then you know what the original unencrypted string was.
If you need two-way encryption/decryption, please have a look at Rexx/
EEC (just released and announcement posted). It provides DES and
BLOWFISH encryption and decryption functions.