Exploiting state obfuscation to detect hardware trojans in NoC network interfaces

We propose to exploit state obfuscation to facilitate hardware Trojan (HT) detection in the network interfaces (NIs) of Network-on-Chips (NoCs). The security of IP cores connected with the NoC infrastructure has been widely studied in previous work; however, countermeasures for the security threats in NoCs themselves lack investigation. In the first phase of our method, we add key bits to the finite state machine of the NI control unit and create dummy states to increase the difficulty for the execution of meaningful attacks. In the second phase, we examine the illegal states and illegal state transitions induced by a wrong key to detect the occurrence of HTs. Simulation results show that our method obtains a HT detection rate of over 97.5% and reduces the probability of a successful HT attack by 71.5%. Our synthesized netlist with a 65nm technology shows that the NI using the proposed method only increases the area overhead by 3.2%, over the baseline NI design.