Flying on Someone Else's Airline Ticket
Slate has published a method for anyone to fly on anyone else’s ticket.
I wrote about this exact vulnerability a year and a half ago.
The vulnerability is obvious, but the general concepts are subtle. There are three things to authenticate: the identity of the traveler, the boarding pass, and the computer record. Think of them as three points on the triangle. Under the current system, the boarding pass is compared to the traveler’s identity document, and then the boarding pass is compared with the computer record. But because the identity document is never compared with the computer record—the third leg of the triangle—it’s possible to create two different boarding passes and have no one notice. That’s why the attack works.