1001 Ways To Implement K

The structure of K allows a fair amount of diversity in the way it can be implemented. However, it is o en not trivial to select the optimal options in given circumstances, and sometimes one may even not be aware of all of K ’s implementation techniques. We here briefly present different techniques, referring to external documents for the details. K defines a family of sponge functions with seven different permutations and most implementation techniques work on all of them. For clarity, however, we take as example K f [1600], the permutation used in the proposed SHA-3 hash function candidates [3].