Known-Key Distinguishers for Some Block Ciphers

Abstract

We present two block cipher distinguishers in a setting where the attacker knows the key. One is a distinguisher for AES reduced the seven rounds. The second is a distinguisher for a class of Feistel ciphers with seven rounds. This setting is quite different from traditional settings. We present an open problem: the definition of a new notion of security that covers attacks like the ones we present here, but not more.

The research described in this paper has been supported by the European Commission under grant number FP6-IST-033563 (Project SMEPP). The information in this document reflects only the authors’ views, is provided as is and no guarantee or warranty is given that the information is fit for any particular purpose. The user thereof uses the information at its sole risk and liability.