10-Round Feistel Is Indifferentiable From An Ideal Cipher

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 transformation. Left unresolved is the number of rounds of a Feistel network that are needed in order for indifferentiability to hold. We improve upon the result of Coron et al. and show that 10 rounds suffice.