Randomized stopping times and provably secure pseudorandom permutation generators.
Michał Kulis, Paweł Lorek, Filip Zagórski · IACR Cryptology ePrint Archive · 2016
Conventionally, key-scheduling algorithm (KSA) of a cryptographic scheme runs for predefined number of steps. We suggest a different approach by utilization of randomized stopping rules to generate permutations which are indistinguishable from uniform ones. We explain that if the stopping time of such a shuffle is a Strong Stationary Time and bits of the secret key are not reused then these algorithms are immune against timing attacks.