And create a desktop application with can decrypt with private key.
This will ensure, nearly 100%, that the CC data is safe to leave in the database
Actually it doesn’t have to be a desktop application. This can be done in javascript.
I also have a Miva Cart with this feature. You can’t see the cc info on any of the orders until you enter a security code. You can then view the CC information for that session. The code is entered in the cart admin. Does not need a separate application.