Multipath Key Establishment for Wireless Sensor Networks Using Just-Enough Redundancy Transmission

In random key predistribution techniques for wireless sensor networks, a relatively small number of keys are randomly chosen from a large key pool and are loaded on the sensors prior to deployment. After deployment, each sensor tries finding a common key shared by itself and each of its neighbors to establish a link key to protect the wireless communication between themselves. One intrinsic disadvantage of such techniques is that some neighboring sensors do not share any common key. In order to establish a link key among these neighbors, a multihop secure path may be used to deliver the secret. Unfortunately, the possibility of sensors being compromised on the path may render such an establishment process insecure. In this work, we propose and analyze the just-enough redundancy transmission (JERT) scheme that uses the powerful maximum-distance separable (MDS) codes to address the problem. In the JERT scheme, the secret link key is encoded in (n, k) MDS code and transmitted through multiple multihop paths. To reduce the total information that needs to be transmitted, the redundant symbols of the MDS codes are transmitted only if the destination fails to decode the secret. The JERT scheme is demonstrated to be efficient and resilient against node capture. One salient feature of the JERT scheme is its flexibility of trading transmission for lower information disclosure.