Trojan Horse Detection for RISC-V Cores Using Cross-Auditing

In security-critical applications, malicious Trojan Horses embedded in a CPU core could impose great threats on the security of an SoC. In this work, we propose a "Trojan-Horse detection framework" using a cross-auditing scheme. Our framework takes a target RISC-V core, and then pairs it up with another reference RISC-V core to conduct the functional simulation using a set of benchmark programs. The "care outputs" of both cores are compared to reveal the potential Trojan Horses in the target core. A set of well-known Trojan Horses are implanted into an open-source RISC-V core to evaluate the effectiveness of this framework. We found that we can successfully detect almost every implanted Trojan Horse as long as it has been activated and manifested by the benchmark programs.