http://us3.php.net/manual/en/book.openssl.php http://us3.php.net/manual/en/book.openssl.php you would store a private key on the server, store the blob in mysq

http://us3.php.net/manual/en/book.openssl.php http://us3.php.net/manual/en/book.openssl.php you would store a private key on the server, store the blob in mysql and encrypt/decrypt as needed. There are other library wrappers as well.