"Cryptography is not Sudoku"

In 2002, David Kahn gave a speech to an NSA audience arguing that "cryptanalysis is dead". However, he went on to say that, "though traditional cryptanalysis may be dead, and may have been mostly a corpse for half a century, other opportunities, perhaps more opportunities, lie ahead." Kahn suggested increased opportunities for interception, side-channel attacks, placing back-doors in exported equipment and software, and so forth.

Maybe Kahn is right. I toy around with the following pet conspiracy theory: the recent promotion of codebreaking puzzles and competitions on the NSA and GCHQ websites is misdirection, and an indication that these agencies aren't actually doing a lot of pure cryptanalysis any more. Why would a codebreaking agency call attention to the fact that it breaks codes? Well, a target nation could think, "NSA and GCHQ are about using mathematics to read ciphers. They might still be breaking the systems of [insert developing country here], but our methods are mathematically impregnable, so we don't need to be concerned". Meanwhile, GCHQ or the NSA are compromising their communications through other means.

Anyway, enough with the tin-foil hat stuff. My apologies. Moreover, there's the occasional rumour that cryptanalysis is actually alive and well, as in the recent case of Iraqi leader Ahmed Chalabi. Wikipedia relates the story:

"In June 2004, it was reported that Chalabi gave U.S. state secrets to Iran in April, including the fact that one of the US's most valuable sources of Iranian intelligence was a broken Iranian code used by their spy services. Chalabi allegedly learned of the code through a drunk American involved in the code-breaking operation. Chalabi has denied all of the charges."

Who knows what lies behind this story? Still, a couple of days ago, a reporter speculated that Chalabi broke the codes himself, as he has a doctorate in mathematics. I very much enjoyed the incredulous comments given at the Orbus Quintus blog by "badgerminor" in response.

Sudoku is great fun, by the way.

Tags: Cryptography, NSA, GCHQ, Chalabi