Friet is an authenticated encryption scheme with built-in protection against fault attacks. It does this by making use of a permutation that operates op a redundant state. The paper includes an analysis of the permutation with respect to diverse propagation properties. Recently a cryptanalytic attack was published that completely breaks Friet. The attack is due to an oversight in the analysis of the permutation. You could say we checked if all the windows were bulletproof glass and doors had double locks but we kept the front door wide open. There is an easy way to modify the Friet permutation to avoid the attack but this may introduce other weaknesses. The work consists of modifying the Friet permutation and doing the analysis that is described in the paper for the modified version. This may take several iterations until a sufficiently good solution is found. The type of work includes pen-and-paper analysis, running experiments with mostly existing code and interpretation of their results. For the latter reading (parts of) papers about cryptanalysis may be required.
If you are interested in this topic, please send an email to Joan Daemen via joan@cs.ru.nl .