php/mysql data encryption

Data Encryption: Description: 1)Step One Once the user is in the check-out (payment) section of a web site, he/she is asked to insert all details such as card type, holder’s name, card number, expiration dates, card code etc. We want all these details to be automatically encrypted (PGP or GPG) on the server and afterwards stored in the database (encrypted also). (Card details or data that i want are stored in a PGP-encrypted form and can only be decrypted and accessed by the appropriate admin via a back-end system.) 2) Step 2 The admin must use the gpg or pgp program accordingly in order to be able to unlock and view this kind of data. Unlocking of data can only be done with the secret key along with the pass phrase. I have been testing some php classes for pgp or gpg and it seems that work really well. No problem to hear for anlternative solution like symetric encryption for example with blowfish that i used in the past but resolving problems with symetric key storage. I would like to recieve an scheme about what you'll do. Contact me for any doubt regards