One of the easiest ways for criminals to steal your credit card information is with a skimmer attached to a gas pump credit card reader. Skimmers are just a second credit card reader placed next to the original; when you insert your card, the skimmer reads the magnetic stripe data and sends it via Bluetooth to a nearby receiver. Modern “chip” cards can protect against that, but gas stations were given an extension to update their pumps — meaning you’re still at risk there. To help law enforcement find those credit card skimmers, computer scientists from the University of California San Diego and the University of Illinois developed a new app called Bluetana.
Unlike other apps on the market that you can download yourself, Bluetana is only available to law enforcement and official inspectors. The apps that you can download usually just work by looking to see if there is a nearby Bluetooth signal with a name that is associated with credit card skimmers. They can’t, however, differentiate between authentic devices with similar names, or precisely locate where the signal is coming from. Bluetana improves on that and makes it easier to locate the skimmers while also reducing false positives.
To develop the Bluetana app, the researchers built a detection algorithm based on data gathered from real skimmers found at 1,185 gas stations. With that data, the app is able to more accurately differentiate between credit card skimmers and legitimate devices that happen to be nearby. It can do that in just seconds, compared to half an hour for a conventional visual inspection. The app also takes signal strength into account, so inspectors can hone in on the skimmer’s location. Bluetana has now been in use for one year, and it has already been used to find 42 credit card skimmers in three different states.