A US government agency has selected cryptographic hash function Keccak as the new official SHA-3 algorithm.
The National Institute of Standards and Technology’s decision to pick the nippy system as the replacement for SHA-1 and SHA-2 marks the end of a six-year competitive process. Five algorithms were left in the running at the end, including crypto-guru Bruce Schneier’s Skein.
Keccak was put together by cryptographers Guido Bertoni, Joan Daemen, Michaël Peeters and Gilles Van Assche, who work for STMicroelectronics and NXP Semiconductors. The NIST team praised the algorithm for its “elegant design and its ability to run well on many different computing devices”. The system is said to take 13 processor cycles on a 2.4GHz Intel Core 2 Duo to process each byte of data, and can be implemented in hardware.
SHA-2 is used in various security technologies, from SSL and SSH to PGP and IPsec, and must be used by law in certain US government applications. Like its predecessor, Keccak converts information into a shortened “message digest”, from which it is impossible to recover the original information, and thwarts attempts to generate an identical digest from two different blocks of input data.
This hashing technique is used in digital signatures, verifying that the contents of software downloads have not been tampered with, and many other cryptographic applications.
Last month Schneier called for the competition to be left open, arguing the longer-bit SHA-2 variants remain secure and that the wannabe SHA-3 replacements do not offer much improvement in terms of speed and security. Getting crypto functions to work on smartphone processors and the like without pulling too much power and draining batteries has become a key design consideration in the design of cryptographic algorithms.
But Schneier accepted NIST’s decision to select Keccak with good grace.
“It’s a fine choice. I’m glad that SHA-3 is nothing like the SHA-2 family; something completely different is good,” he said.
“Congratulations to the Keccak team. Congratulations – and thank you – to NIST for running a very professional, interesting, and enjoyable competition. The process has increased our understanding about the cryptanalysis of hash functions by a lot.
“I know I just said that NIST should choose ‘no award’, mostly because too many options makes for a bad standard. I never thought they would listen to me, and – indeed – only made that suggestion after I knew it was too late to stop the choice.” ®