Algebraic Attack on Small Scale Variants of AES using Compressed Right Hand Sides

Abstract

The Advanced Encryption Standard is probably the most used symmetric encryption cipher in use today, which makes it particularly interesting for cryptanalysis. This thesis attacks smallscale variants of AES through a particular branch of algebraic cryptanalysis known as Compressed Right-Hand Sides. We see some success, as we are able to break for the first time three rounds of a 32-bit small-scale variant. We also make an interesting discovery, in that we get indications that some plaintext values result in easier-to-break small-scale instances.