05148645

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05148645 Pieprzyk, Josef Zhang, Xian-Mo Goli\'c, Jovan Dj. Characterisations of extended resiliency and extended immunity of S-boxes. Won, Dongho (ed.) et al., Information security and cryptology -- ICISC 2005. 8th international conference, Seoul, Korea, December 1--2, 2005. Revised selected papers. Berlin: Springer (ISBN 3-540-33354-1/pbk). Lecture Notes in Computer Science 3935, 210-228 (2006). 2006 Berlin: Springer EN Extended Resiliency Extended Immunity Divide-and- Conquer Algebraic Attacks

doi:10.1007/11734727

Summary: New criteria of extended resiliency and extended immunity of vectorial Boolean functions, such as S-boxes for stream or block ciphers, were recently introduced. They are related to a divide-and-conquer approach to algebraic attacks by conditional or unconditional equations. Classical resiliency turns out to be a special case of extended resiliency and as such requires more conditions to be satisfied. In particular, the algebraic degrees of classically resilient S-boxes are restricted to lower values. In this paper, extended immunity and extended resiliency of S-boxes are studied and many characterisations and properties of such S-boxes are established. The new criteria are shown to be necessary and sufficient for resistance against the divide-and-conquer algebraic attacks by conditional or unconditional equations.