A power efficient link-layer security protocol (LLSP) for wireless sensor networks

Wireless sensor networks (WSNs) rely on wireless communications, which is by nature a broadcast medium and is more vulnerable to security attacks than its wired counterpart due to lack of a physical boundary. Anybody with an appropriate transceiver can eavesdrop on, intercept, inject, and even alter the transmitted data. Security services are, therefore, urgently needed to ensure effective access control and information confidentiality. WSNs are severally energy constrained since many sensor networks are designed to operate unattended for a long time and battery recharging or replacement may be infeasible or impossible. To optimize the limited capability of the sensor nodes, security requirements are generally abandoned. This leaves WSNs under security attacks, which could cause more battery power consumption and reduced lifespan of the WSNs. In the worst case, an adversary may be able to undetectably take control of some sensor nodes, compromise the cryptographic keys and reprogram the sensor nodes. In this paper, a power efficient link-layer security protocol (LLSP) is proposed. LLSP provides node authentication, message integrity check, and message semantic security at a minimal cost by minimizing the security overhead in data packet and applying only symmetric security algorithms. The security analysis and performance analysis show that LLSP is secure and computationally efficient.