PASCAL: Timing SCA Resistant Design and Verification Flow

Abstract: A large number of crypto accelerators are being deployed with the widespread adoption of IoT. It is vitally important that these accelerators and other security hardware IPs are provably secure. Security is an extra functional requirement and hence many security verification tools are not mature. We propose an approach/flow-PASCAL-that works on RTL designs and discovers potential Timing Side-Channel Attack(SCA) vulnerabilities in them. Based on information flow analysis, this is able to identify Timing Disparate Security Paths that could lead to information leakage. This flow also (automatically) eliminates the information leakage caused by the timing channel. The insertion of a lightweight Compensator Block as balancing or compliance FSM removes the timing channel with minimum modifications to the design with no impact on the clock cycle time or combinational delay of the critical path in the circuit.