A cryptographic hash function converts an arbitrary-length message into a fixed-length digest, and it is a fundamental step in the efficient implementation of electronic messages. Back in 2004, significant attacks on the standard hash functions of that time were getting published everywhere. These attacks almost completely broke MD5, SHA-0 and later on SHA-1.
At that time, NIST announced that it would phase out SHA-1 and replace it with the more stable SHA-2. However being algorithmically similar to SHA-1, NIST feared that SHA-2 might itself get broken in the near future, and in Nov 2007 announced a competition to select a new standard for cryptographic hashing, SHA-3.
The competition ended Oct 2012 and out of 64 submissions Keccak was declared the winner. Keccak (pronounced “ketchak”) was designed by a cryptographic group from Belgium and Italy, namely Guido Bertoni, Joan Daemen, Gilles Van Assche of STMicroelectronics and Michaël Peeters of NXP Semiconductors. Joan Daemen is also a co-author of the block cipher Rijndael algorithm which won the AES competition.
Later research on the cryptanalysis of hashing algorithms improved the confidence in SHA-2 showing that it can still be safely used. However, NIST still slightly favors Keccak for being an entirely different algorithm.
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