How does BTS store its data?
Access cards contain ID numbers, and nothing else. All account information is maintained on a SQL database backend. I don’t know how much the backend configuration varies between installations, but that’s how it works at Georgia Tech. Many BTS cards have barcodes on the front. According to my CueCat scanner, this is just the card ID number, which is probably identical to the number stored on the mag stripe. Perhaps someone with a mag stripe reader can verify this. In particular, cards do not contain account balances. It is not possible to increase your balance just by rewriting the mag stripe. (This was possible at some point in the past.
