The semiconductor design industry has globalized and it is economical for the chip makers to get services from the different geographies in design, manufacturing and testing. Globalization raises the question of trust in an IC(Integrated Circuit) chip. These reason, supply chain of Hardware product enforce the Hardware safety. Trust-HUB provides benchmarks of Hardware Backdoor. This paper analyzes taxonomy of Trust-HUB’s Hardware Backdoor benchmarks. Also, we selected main researchable subjects to study hardware backdoors circuit feature and signals.