There's alot of carts out there to select from, but when it comes down to security. . . what form of security is most secure for a cart?

I've seen some uses SSL to securely fill out information between the browser and the server. Viewing orders in the admin also require a SSL page to prevent a man in the middle attack to intercept something.

However, would you go as far as using PGP encryption perhaps? What are the some of the methods other carts employ when it come down to security?