Originally Posted by StuartD

The problem isn't that its' not paper, they do print out paper receipts....
it's that the code is secure, no one's allowed to review it. No one's allowed to double check the systems, no one's allowed to watch the process in action. No one's allowed to verify that everything's ok before, during or after.

That's just wrong. If it's supposed to be so important, there'd be 2nd, 3rd, 4th and 5th measures taken to ensure it's right.