Comment Re:NSA has cribs? (Score 1) 394
Nitpick: Nearly all ciphers are symmetric ciphers (except for the asymmetric ones
:-)), and many of them are very vulnerable to known plaintext attacks. But there are plenty of symmetric ciphers which are, as far as we know, resistant to known plaintext, chosen plaintext and even more sophisticated attacks. Such as AES-256, which seems to be the cipher used here.
Turns out the NSA has worked out a practical known plaintext break for AES (including -256), it's at offset 459139182 of the insurance file.
:-)
Seriously, it's very, very unlikely that the NSA can break AES, because if they could they'd have to be concerned that someone else might be able to do it as well. The NSA's job is national security, which means protecting important national resources, including the economy, not just spying. So the only way they'd let us keep using AES all over the place after breaking it themselves is if they could be absolutely certain that no one else could do what they did, which would require an unimaginable level of arrogance -- and a very unspook-like way of thinking.