Insertion of random delay with context-aware dummy instructions generator in a RISC-V processor

Embedded systems are vulnerable to side channel and fault injection attacks. These two types of attacks can be slightly complicated by using temporal desynchronization methods. In this article we propose a new hardware solution to efficiently insert dummy instructions in run time for a general-purpose processor. The main contribution of this solution is to contextualize these dummy instructions, making them less distinguishable and more variable with a minimal spatial overhead of 2.96% and a 4.27% additional consumption and no code size impact on a eV32E40P RISC V processor. As a result, they bring a significant resistance to resynchronization methods.