The Keccak sponge function family

Guido Bertoni1, Joan Daemen1,2, Michaël Peeters1 and Gilles Van Assche1

2Radboud University




Software and other files


The figures above are available under the Creative Commons Attribution license. In short, they can be freely used, provided that attribution is properly done in the figure caption, either by linking to this webpage or by citing the article where the particular figure first appeared.


Note on Keccak parameters and usage

25 February 2010

The Keccak sponge function family is characterized by three parameters: the bitrate r, the capacity c and the diversifier d. In the Keccak specifications we propose four instances that can be taken as functions for the four (fixed) output lengths NIST requires for SHA-3 and a variable-output-length instance, with default values for the parameters.

Whilst we are happy with our choice, there are other valid parameter choices that NIST or others may prefer. We publish a new note, in which we discuss our choice of parameters and other possible ways of using the Keccak family.