Code updates based on minimal backbone and group key management for secure sensor networks

Code update in sensor networks is a useful technology to update codes to change the functionality or to correct bugs of the existing code. However, sensor networks are susceptible to various attacks because they are deployed in open and unprotected environments. It is necessary to use effective mechanisms to protect sensor nodes against attacks. In this paper, we propose a secure code update mechanism over the energy-efficient minimum virtual backbone reducing the number of broadcasting packets using RSSI (Received Signal Strength Indicator) values. We also propose a group key establishment and rekeying mechanism which provides authentication among the entities for code update. Our mechanism considers all security requirements such as confidentiality, integrity and authentication to defend the battery exhaustion attack, DoS attacks, the routing attacks, etc. during the code update. Simulation results show that our mechanism significantly reduces the number of transmitted messages, the energy consumption and the computation overhead for the secure code update in comparison to other existing secure code update mechanisms. We also prove that our group key mechanism is efficient and much more secure than compared ones.