Strong 8-bit Sboxes with Efficient Masking in Hardware [chapter]

Erik Boss, Vincent Grosso, Tim Güneysu, Gregor Leander, Amir Moradi, Tobias Schneider
2016 Lecture Notes in Computer Science  
Block ciphers are arguably the most important cryptographic primitive in practice. While their security against mathematical attacks is rather well understood, physical threats such as side-channel analysis (SCA) still pose a major challenge for their security. An effective countermeasure to thwart SCA is using a cipher representation that applies the threshold implementation (TI) concept. However, there are hardly any results available on how this concept can be adopted for block ciphers with
more » ... arge (i.e., 8-bit) Sboxes. In this work we provide a systematic analysis on and search for 8-bit Sbox constructions that can intrinsically feature the TI concept, while still providing high resistance against cryptanalysis. Our study includes investigations on Sboxes constructed from smaller ones using Feistel, SPN, or MISTY network structures. As a result, we present a set of new Sboxes that not only provide strong cryptographic criteria, but are also optimized for TI. We believe that our results will found an inspiring basis for further research on high-security block ciphers that intrinsically feature protection against physical attacks.
doi:10.1007/978-3-662-53140-2_9 fatcat:hj4qf4e6izhknnvnq4wtu3lqga