Design Of Hardware Trojan Circuits Based On An Advanced Encryption Standard Algorithm

Globalization of the semiconductor design and fabrication process is animportant feature of modern Integrated Circuit (IC), which limits the control ofcustomer over IC supply chain. Adversary may secretly alter the original circuit byimplanting malicious Hardware Trojans either during design or fabrication. HardwareTrojans seriously threaten the information security since attackers can insert maliciouslogics to cryptographic chips which help them easily get the secret key. As the studyof Hardware Trojans design methods and detection technologies are both still in itsinfancy, research on the Trojan design methods would contribute to the developmentof Trojan detection technologies.Therefore this paper carried out a detailed study on Hardware Trojans designtechnologies by taking a cryptographic algorithm as the target circuit. Because of thewidespread use of Advanced Encryption Standard (AES) algorithm, we completed thehardware design of an AES algorithm. Both the block length and the key length of thisAES algorithm are128bits. The logic synthesis, physical design and simulation of theAES module have been completed and the result shows that the function of the circuitis correct. Lately it would be taped out in Global Foundry0.35μm CMOS technology.On the basis of the above work, a combinational Trojan and a sequential Trojan whichcan damage the functions of the cryptographic chip were designed as well as a Trojanbased on logical comparison which can steal the key information. All of these Trojanswere implanted to the AES target circuit and the simulations were carried out byFPGA. The simulation result shows that all of these Trojans work well.