Authentication in Reprogramming of Sensor Networks for Mote Class Adversaries

Abstract

Reprogramming is an essential service for wireless sensor networks. Authenticating reprogramming process is impor-tant as sensors need to verify that the code image is truly from a trusted source. There are two ways to achieve authentica-tion: public key based and symmetric key based. Although previous work has shown that public key authentication is feasible on sensor nodes if used sparingly, it is still quite ex-pensive compared to symmetric key based approach. In this paper, we propose a symmetric key based protocol for au-thenticating reprogramming process. Our protocol is based on the secret instantiation algorithm from [5, 11], which re-quires only O(log n) keys to be maintained at each sensor. We integrate this algorithm with the existing reprogramming protocol. Through simulation, we show that it is able to au-thenticate reprogramming process at very low communica-tion cost, and has very short delay