Anne Canteaut
INRIA
On some algebraic properties of Keccak
The inner permutation in Keccak consists of 24 iterations of a simple quadratic function, chosen for its low implementation cost. A natural question is then to determine whether some of the algebraic properties of this round function can introduce some weaknesses in the whole permutation. Most notably, we investigate how the algebraic degree of the permutation (and of its inverse) increases with the number of iterations. In particular, it can be shown that, for 24 rounds, the cost for exploiting the involved algebraic properties is much higher than the cost of generic attacks. This is a joint work with Christina Boura.