Proactive code verification protocol in wireless sensor network

For WSN(Wireless Sensor Network) to provide reliable service, authentication is one of the most important requirements. The authentication usually means the entity authentication, but owing to the data centric nature of sensor network, much more importance must be put on the authentication (or attestation) for code of sensor nodes. The naive approach to the attestation is for the verifier to compare the previously known memory contents of the target node with the actual memory contents in the target node, but it has a significant drawback. In this paper, we show what the drawback is and propose a countermeasure. The basic idea of our countermeasure is not to give the malicious code any memory space to reside by cleaning the target node's memory space where the malicious code can reside. This scheme can verify the whole memory space of the target node and provides extremely low probability of malicious code's concealment without depending on accurate timing information unlike SWATT[1]. We provide this verification method and show the performance estimation in various environments.