Secured Bus as a Countermeasure against Covert Channels: NEORV32 Case Study

Secured Bus as a Countermeasure against Covert Channels: NEORV32 Case Study

연구 분야: Cryptography

학회: 2024 IEEE 25th Latin American Test Symposium (LATS)

Cache-based Covert Channels are a significant threat for the security of systems built around a CPU. We evaluated a countermeasure taking advantage of a secured bus added in the CPU core with very little intrusiveness at the system level. This bus is used to bypass the data cache and other leaking elements when memory accesses are related to sensitive data or functions. We show on the NEORV32 CPU core that hardware overheads are negligible and a comparison with the use of the fence.t instruction illustrates noticeable gains in terms of secured execution speed.