Known-key distinguisher on round-reduced 3D block cipher

Abstract

3D block cipher is an AES-based block cipher which has a three-dimensional state. Besides some traditional attacks, Knudsen and Rijmen introduced a new tool, known-key distinguisher, to identify the weak pseudo-randomness of a block cipher. In this paper, we present a known-key distinguisher on 15-round 3D cipher, which has 22 rounds in total. In our attack, we use the rebound attack to construct two differential paths, and integrate them by a technique of solving a system of nonlinear equations. It can be done with a negligible complexity and sufficient random degrees are provided for the subsequent attack. We extend the differential trail to 15 rounds and give a known-key distinguisher based on the 15-round differential path. The complexity of finding a right pair is 2 200, which is clearly lower than the complexity of generic attack. © 2012 Springer-Verlag Berlin Heidelberg.