On Tue, Jun 05, 2007 at 09:28:00AM -0500, Ron Johnson wrote: > > If he is a CC customer, the system (which I am DBA of) bills his > card directly, saving the customer much time and effort.
So surely what you have is a completely separate system that has exactly one interface to it, that is signaled to provide a transaction number and that only ever returns such a transaction number to the "online" system, and that is very tightly secured, right?
It is possible to make trade-offs in an intelligent manner, for sure, but you sure as heck don't want that kind of data stored online with simple reversible encryption.
A
Unfortunately you still need to store them somewhere, and all systems can be hacked. Yes its a good idea to store them on a separate system and this is an important part of designing your systems to ensure that the simple user interface is somehow limited.
