Differential Power Analysis of 8-Bit Datapath AES for IoT Applications

The security issue of Internet of Things (IoT) applications causes wide concern nowadays. Lightweight encryption circuits are preferred in IoT due to its severe restrictions of chip area and power consumption, among which, 8-bit datapath Advanced Encryption Standard (AES) is popular for its mature algorithm, compact architecture and low power consumption. However, it is also subject to the side channel analysis (SCA) attack, which is rarely mentioned. In this paper, a novel differential power analysis (DPA) attack method specialized for 8-bit datapath AES is proposed, which exploits the correlation between the power consumption of S-Box and processed data. The method can traverse all the possibilities. As a result, it is effective for almost all the existing 8-bit AES architecture in theory. The first round of encryption is adopted as the target round, avoiding the complicated computing in AES algorithm to reduce the cost of attack and increase the success rate and efficiency. The effectivity of this kind of method is verified by FPGA implementation on SAKURA-G board, with a minimum of 3681 power traces to crack the correct sub-key.