SHA 3 is announced

NIST has chosen SHA 3 and announced it. As they put it in their announcement, one reason this is important is if SHA 2 falls hard we have an insurance policy. The algorithm is Keccak "(pronounced “catch-ack”)". I commend the winners and look forward to playing with the new technology after the reference algorithm is published. One of the things I am most excited about is to see how deterministic it is. We know that two different messages produce a different digest, but if they are very similar, will the digest be similar. There are some interesting security implications including finding modified copyrighted documents if the digest allows similar documents to produce similar digests.