| In recent years, wireless sensor networks (WSNs) have found use in a variety of different applications including environmental monitoring, battlefield strategy planning, health monitoring, and so forth. With many of the applications involving communication of highly sensitive data, security becomes a primary concern. Generally, features such as data integrity, data, authentication and information confidentiality are required for secure communications. However, incorporating these functions in WSNs is challenging due to the specific constraints such as limited memory and restricted energy supply. These constraints prohibit conventional security techniques from being directly applied to WSNs. As a, result, new energy efficient, protocol designs are highly desired for WSNs.; In this thesis, we investigate the importance of the link-layer security service in WSNs and propose an energy efficient link-layer security protocol (LLSP) to reduce the energy consumption in the network. The LLSP protocol is based on the security protocol for TinyOS applications called TinySec, which provides node authentication, message confidentiality and access control. In addition to providing the security services of TinySec, LLSP provides replay protection while reducing the security overhead per packet by 17%. Throughout this thesis we analyze and compare the performance as well as the energy consumption of TinySec and LLSP security protocols. Furthermore, we investigate the throughput of the system over both error-free and lossy channels using the LLSP protocol. The simulation results demonstrate that LLSP outperforms TinySec in terms of energy reduction and throughput performance. |
