Hacking TSA PreCheck

I have a hard time getting worked up about this story:

I have X’d out any information that you could use to change my reservation. But it’s all there, PNR, seat assignment, flight number, name, ect. But what is interesting is the bolded three on the end. This is the TSA Pre-Check information. The number means the number of beeps. 1 beep no Pre-Check, 3 beeps yes Pre-Check. On this trip as you can see I am eligible for Pre-Check. Also this information is not encrypted in any way. What terrorists or really anyone can do is use a website to decode the barcode and get the flight information, put it into a text file, change the 1 to a 3, then use another website to re-encode it into a barcode. Finally, using a commercial photo-editing program or any program that can edit graphics replace the barcode in their boarding pass with the new one they created. Even more scary is that people can do this to change names. So if they have a fake ID they can use this method to make a valid boarding pass that matches their fake ID. The really scary part is this will get past both the TSA document checker, because the scanners the TSA use are just barcode decoders, they don’t check against the real time information. So the TSA document checker will not pick up on the alterations. This means, as long as they sub in 3 they can always use the Pre-Check line.

What a dumb way to design the system. It would be easier — and far more secure — if the boarding pass checker just randomly chose 10%, or whatever percentage they want, of PreCheck passengers to send through regular screening. Why go through the trouble of encoding it in the barcode and then reading it?

And — of course — this means that you can still print your own boarding pass.

On the other hand, I think the PreCheck level of airport screening is what everyone should get, and that the no-fly list and the photo ID check add nothing to security. So I don’t feel any less safe because of this vulnerability.

Still, I am surprised. Is this the same in other countries? Lots of countries scan my boarding pass before allowing me through security: France, the Netherlands, the UK, Japan, even Uruguay at Montevideo Airport when I flew out of there yesterday. I always assumed that those systems were connected to the airlines’ reservation databases. Does anyone know?

Posted on October 26, 2012 at 6:46 AM • 52 Comments