The NSA sure breaks a lot of "unbreakable" crypto. This is probably how they do it.

There have long been rumors, leaks, and statements about the NSA "breaking" crypto that is widely believed to be unbreakable, and over the years, there's been mounting evidence that in many cases, they can do just that. Now, Alex Halderman and Nadia Heninger, along with a dozen eminent cryptographers have presented a paper at the ACM Conference on Computer and Communications Security (a paper that won the ACM's prize for best paper at the conference) that advances a plausible theory as to what's going on. In some ways, it's very simple -- but it's also very, very dangerous, for all of us. (more")