Fast DDP-based ciphers: from hardware to software

Data-dependent (DD) permutations (DDP) that are very suitable to cheap hardware implementation have been introduced as a cryptographic primitive for the design of fast firmware and software encryption systems. DDP can be performed with so called controlled permutation boxes (CPB) which are fast white implemented in cheap hardware. The latter defines the efficiency of the embedding of CPB in microcontrollers and microprocessors when adding a new fast instruction that allows one to perform DDP. Software and firmware encryption algorithms combining DDP with fast arithmetic operations are described.