Wireless Registers May Expose Your Credit Card
flynt writes: "Found this article about people sitting in Best Buy parking lots with wireless sniffers and intercepting credit card numbers that the wireless cash registers inside the store are beaming about. Gives more credence to the idea of one time use credit card numbers. Now you don't even have to be online to have your number stolen."
Lock down all ports on the server except SSH, and force the cash register client machines to tunnel through SSH for everything. I use it at home, work and university. It's better to be over security-conscious than being to relaxed about it.
However, that's just covering up the symptoms of a greater problem. It would be better if credit cards used a public/private key system, where the acocunt number is sent to the central server which responds with a random encryption challenge, then a chip on the card encrypts the string using it's key and replies. That way no useful security information is being pased around for others to intercept and use.
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Someone down the line knows your credit card number. If you hand your card to the person at the register, then you are placing trust in them. If your information is stolen by a 3rd party, then it is because of the incompetence of whoever you placed your trust in.
According to the article, Best Buy has since stopped using wireless cash registers. Still, I think the problem is not with wireless itself, but the particular implementation Best Buy was using. Couldn't they simply encrypt the data?
Of course, credit cards are inherently problematic. Although I use credit cards, I think the system is poorly designed. Basically, you say to a guy, "here's a key to my safe, please only take what you need." IMO, it should be the reverse. We should *give* them the money, possibly by authorizing a transaction via your bank (a cell phone would be the best way, so you don't have to trust an in-store terminal) Thus, everyone would be able to give, but not take. As it stands, credit cards have the worst security of anything. It's ironic too, since a lot of us computer enthusiasts will rant all day about how everyone should be using ssh and GPG, yet we give our login and password to the waitress next time we eat.
Like you ever did need to be online to get your number stolen - easiest way to steal credit card numbers is to get a job in a retail outlet and record numbers of customers cards.
This is *the* classic error in security thinking - only consider the hardware, ignore the human factors.