Analysis on Key-leakage Hardware Trojan of SM4 Algorithm
Yue Chen, Zhenhui Zhang, Liji Wu, Xiangmin Zhang, Yijun Yang · 2018
The cryptographic algorithm is an important part of the security system. Its purpose is to ensure that the attacker can not obtain the correct transmissive information if he has stolen the ciphertext but has not the secret key between the sender and the receiver. Therefore, the key is a part of the cryptographic algorithm, and the leakage of the key will lead to security failure. In this paper, a key leakage Trojan circuit was designed and the original circuit was SM4, a Chinese block cipher algorithm standard. The trigger part is composed of sequential and combinational circuits, so the hardware Trojan would be triggered only when the conditions are met for both two kinds of circuits. One of its components is a counter, with timing function if necessary. The scheme was verified on a DE2-115 Altera cyclone-IV FPGA board. And the total registers increasing caused by the hardware Trojan is as low as 0.26%.