RSA implementation, please comment.

Hi All; I've come up with a solution and I'd like some feedback on whether or not it is secure. SYNOPSIS: Is Crypt::RSA secure acceptable in open source if the private key password is in a browser cookie? DETAILS: We're running a pretty basic LAMPS system with MySQL 5.1 and Perl 5.8. The client asked me to devise "a secure way to save credit card