Seasoning effect based side channel attacks to AES implementation with phase change memory

Abstract

Side channel attacks have received much attention as of recent. Compared with cryptanalysis that focus on the algorithms themselves, side channel attacks are usually much more practical and realistic. Side channel attack is closely related to hardware and implementations. Many cryptographic algorithms that are secure by themselves become insecure when they are poorly implemented or are running on devices with special properties. In this work, we examine the probability of side channel attacks on phase change memory which is envisioned as a candidate of universal memory to replace DRAM or SRAM. The attacks exploit the seasoning effect of phase change memory, a phenomenon of PCM cell behavior change as a function of operative cycles. We conducted detailed experiments using PCM modeling tools that accurately simulate the seasoning effect of PCM cells. The results show that for pipelined AES cipher that is not properly implemented when using PCM as the storage device, side channel attacks may lead to serious security risks. We also provide suggestions for secure implementation of AES to prevent such attacks.