Energy-efficient multi-key security scheme for wireless sensor network

This paper proposes multi-key encryption scheme and engine architecture (MKE) that increases security and optimizes energy efficiency of sensor networks, while minimizing modifications to existing implementations. The scheme improves security of AES against correlation power analysis (CPA) attack by employing MKE engine, breaking the correlation between power consumption and the used key. Other schemes utilize complex hardware designs, for example by using the inhomogeneous s-boxes that reduce energy efficiency of the engine. In contrast, the proposed hardware engine uses a randomly sequence of few keys to encode subsequent blocks of a messages. Additionally, the scheme improves security of AES against brute-force attacks for a given key size by utilizing multiple keys to encrypt subsequent blocks of a message. In contrast, a typical security upgrade would require a larger key size and encryption engine, which would increase cost and energy consumption of the devices. Both analytical and simulation results are presented in this paper.