Jeremy A. Hansen writes "Bruce Schneier gives us an update on some ongoing cryptanalysis of AES. 'Over the past couple of months, there have been two new cryptanalysis papers on AES. The attacks presented in the paper are not practical — they're far too complex, they're related-key attacks, and they're against larger-key versions and not the 128-bit version that most implementations use — but they are impressive pieces of work all the same. This new attack, by Alex Biryukov, Orr Dunkelman, Nathan Keller, Dmitry Khovratovich, and Adi Shamir, is much more devastating. It is a completely practical attack against ten-round AES-256.' While ten-round AES-256 is not actually used anywhere, Schneier goes on to explain why this shakes some of the cryptology community's assumptions about the security margins of AES."