Characterisations of Extended Resiliency and Extended Immunity of S-Boxes [chapter]

Josef Pieprzyk, Xian-Mo Zhang, Jovan Dj. Golić
2006 Lecture Notes in Computer Science  
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
more » ... lues. In this paper, extended immunity and extended resiliency of Sboxes 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.
doi:10.1007/11734727_19 fatcat:6lt6vxeu3fbp5drby3m5xttowa