Advanced Encryption Standard (AES) is the most popular symmetric block cipher algorithm. The commonly used mode of operation in AES is the Electronic Code Book (ECB) mode. In the past, side channel attacks have been shown to be effective in breaking the secret keys used with AES, while AES is operating in the ECB mode. AES defines a number of advanced modes (Cipher Block Chaining - CBC, Cipher feedback – CFB, Output Feedback – OFB, and Counter – CTR) of operation that are built on the top of EBC mode to enhance security. In this paper, a study is conducted on the vulnerabilities against power analysis based side channel attacks of all such modes of operations, implemented on hardware circuits for low power and high speed embedded systems. Through this study I came to know that AES is vulnerable in all modes of operation against Correlation Power Analysis (CPA) attack, one of the strongest power analysis based side channel attacks. The study also quantifies the level of difficulty in breaking AES in different modes by calculating the number of power traces needed to arrive at the complete secret key. From the study I understood that the counter mode of operation provides a balance in between area and power while maintaining adequate resistance for power analysis attacks than when used with other modes of operations. This paper shows that the previous recommendations for the rate of change in the keys and vectors is grossly inadequate, and suggest that it must be changed at least every 210 encryptions in CBC mode and 212 encryptions in CFB, OFB and CTR modes in order to resist power analysis attacks. Cite the ArticleAleena Rose Valson, Elsa Elias. A Study on Power Analysis Based Side Channel Attacks on Advanced Modes of AES. Research & Reviews: A Journal of Embedded System & Applications. 2016; 4(1): 12–20p.
