The Skein hash function and Threefish block cipher

The National Institute of Standards and Technology is holding a competition to design a new hash function to replace the current SHA family of functions and become SHA-3. The deadline for submissions was today, and the submissions will be evaluated over the coming years until a final proposed standard is made in 2012. Bruce Schneier posted some information about his team’s entry, Skein, and the whole selection process:

NIST is holding a competition to replace the SHA family of hash functions, which have been increasingly under attack. (I wrote about an early NIST hash workshop here.)

Skein is our submission (myself and seven others: Niels Ferguson, Stefan Lucks, Doug Whiting, Mihir Bellare, Tadayoshi Kohno, Jon Callas, and Jesse Walker).

The selection process will take around four years. I’ve previously called this sort of thing a cryptographic demolition derby — last one left standing wins — but that’s only half true. Certainly all the groups will spend the next couple of years trying to cryptanalyze each other, but in the end there will be a bunch of unbroken algorithms; NIST will select one based on performance and features.

The Skein hash function is based on a the Threefish block cipher, which is also released as part of the submission. Source has been released to the public domain, which you can download from the Skein website.

Schneier on Security: The Skein Hash Function
Skein Submission Paper – Design, Usage, and Preliminary Cryptanalysis (PDF)
The Skein Hash Function Family Website

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