Against transient-steady effect attack using time check blocks

Transient-steady effect (TSE) attack is a new type of fault attack which exploits the phenomenon that the output of a combinational circuit keeps a temporal value for a while before it finally switches to the correct value and breaks the key by injecting a clock glitch to capture the temporal value. In order to efficient against TSE attack, we propose our countermeasure based on a time check blocks (TCB). We first make a theoretical analysis for the TSE attack, and point out the transient value is exists as long as the two circuits in operation with different critical paths. Then we present our resist ideas. The proposed idea is to use the TCB to check whether the clock signal is abnormal and change the output of the circuit if there is a clock glitch be detected, this will make the attacker can not get the correct transient value. Furthermore, we point out that our countermeasure can be used to against attacks which based on injecting a clock glitch, such as typical Fault Sensitivity Analysis (FSA). Experiments are carried out to verify our countermeasure, and the results demonstrate that the proposed TCB can successfully detect the abnormal clock, and our countermeasure can resist TSE attacks effectively.