10-round Feistel is indifferentiable from an ideal cipher

May 6, 2016

Aishwarya Thiruvengadam


10-round Feistel is indifferentiable from an ideal cipher

Time:   11:00am
Location:   Meeting room 302 (Mountain View), level 3

We revisit the question of constructing an ideal cipher from a random oracle. Coron et al.~(Journal of Cryptology, 2014) proved that a 14-round Feistel network using random, independent, keyed round functions is indifferentiable from an ideal cipher, thus demonstrating the feasibility of such a construction. Left unresolved is the best possible efficiency of the transformation. We improve upon the result of Coron et al. and show that 10 rounds suffice. This is joint work with Dana Dachman-Soled and Jonathan Katz.