Paper 2015/1069

Indifferentiability of 8-Round Feistel Networks

Yuanxi Dai and John Steinberger

Abstract

We prove that a balanced 8-round Feistel network is indifferentiable from a random permutation. This result comes on the heels of (and is part of the same body of work as) a 10-round indifferentiability result for Feistel network recently announced by the same team of authors. The current 8-round simulator achieves similar security, query complexity and runtime as the 10-round simulator and is not significantly more involved. The security of our simulator is also slightly better than the security of the 14-round simulator of Holenstein et al. for essentially the same runtime and query complexity.

Note: We accidentally uploaded an outdated version of the paper.