Security Analysis and Improvement of a Secure and Distributed Reprogramming Protocol for Wireless Sensor Networks

Wireless reprogramming in a wireless sensor network (WSN) is the process of propagating a new code image or relevant commands to sensor nodes. As a WSN is usually deployed in hostile environments, secure reprogramming is and will continue to be a major concern. While all existing insecure/secure reprogramming protocols are based on the centralized approach, it is important to support distributed reprogramming in which multiple authorized network users can simultaneously and directly reprogram sensor nodes without involving the base station. Very recently, a novel secure and distributed reprogramming protocol named SDRP has been proposed, which is the first work of its kind. However, in this paper, we identify an inherent design weakness in the user preprocessing phase of SDRP and demonstrate that it is vulnerable to an impersonation attack by which an adversary can easily impersonate any authorized user to carry out reprogramming. Subsequently, we propose a simple modification to fix the identified security problem without losing any features of SDRP. Our experimental results demonstrate that it is possible to eliminate the design weakness by adding 1-B redundant data and that the execution time of the suggested solution in a 1.6-GHz laptop PC is no more than 1 ms. Therefore, our solution is feasible and secure for real-world applications. Moreover, we show that, in order to further improve the security and efficiency of SDRP, any better established identity-based signature algorithm can be directly employed in SDRP. Based on implementation results, we demonstrate efficiency improvement over the original SDRP.