Energy-efficient In-network encryption/decryption for wireless body area sensor networks

Advances in wearable devices and pervasive computing provide unprecedented opportunity for ubiquitous realtime e-Healthcare and patient monitoring by placing wirelessly connected sensors in, on, and around the body of patients. Due to the privacy-sensitive and mission-critical nature of these wireless body area sensor networks (WBASNs), as well as the desire to use them for long-time uninterrupted monitoring of patients´ vital physiological signals, the privacy/security and energy efficiency of WBASNs are of primary concerns. In this paper, we propose a novel In-network AES Equivalent (IAE) mechanism to protect the security/privacy and maintain good energy efficiency for WBASNs at the same time. IAE achieves this goal by outsourcing part of the energy-consuming cryptographic operation to other deliberately-selected peer sensor nodes so as to balance the energy consumption of the entire network. An analytical model is proposed to characterize the computation and communication energy consumption of IAE, based on which we optimize the outsourcing under given security constraints. Through extensive simulations, we verify the effectiveness and efficiency of the proposed mechanism in prolonging the network lifetime under given security requirements.