This paper concerns the problem of reducing the implementation cost of the switchable data-dependent operations (SDDOs) that are a new cryptographic primitive oriented to the design of fast ciphers suitable to applications in constrained environments. The SDDOs are performed with the controlled substitution-permutation networks that transforms binary vectors depending on some controlling data subblock. Three new desings of the SDDOs are proposed. The first one is characterized by dividing the controlling data subblock into two subvectors that are extended in correspondence with mirror symmetry. Reversing the operation mode is defind by swapping the subvectors. The second one is characterized by using the inversion of the controlling bits as the switching mechanism. The third one is characterized by using two mutual inverse controlled operational boxes and provides construction of the SDDOs of different orders. The last design supplements the known particular constructions of SDDOs hav...
Nikolay A. Moldovyan