Side-channel countermeasures utilizing dynamic logic reconfiguration: Protecting AES/Rijndael and Serpent encryption in hardware

Dynamic logic reconfiguration is a concept that allows for efficient on-the-fly modifications of combinational circuit behavior in both ASIC and FPGA devices. The reconfiguration of Boolean functions is achieved by modification of their generators (e.g., shift register-based look-up tables) and it can be controlled from within the chip, without the necessity of any external intervention. This hardware polymorphism can be utilized for the implementation of side-channel attack countermeasures, as demonstrated by Sasdrich et al. for the lightweight cipher PRESENT.