Multiple Protocol Attacks
In 1997, I wrote about something called a chosen-protocol attack, where an attacker can use one protocol to break another. Here’s an example of the same thing in the real world: two different parking garages that mask different digits of credit cards on their receipts. Find two from the same car, and you can reconstruct the entire number.
I have to admit this puzzles me, because I thought there was a standard for masking credit card numbers. I only ever see all digits except the final four masked.