A TPM-enabled remote attestation protocol (TRAP) in wireless sensor networks

Given the limited resources and computational power of current embedded sensor devices, memory protection is difficult to achieve and generally unavailable. Hence, the software run-time buffer overflow that is used by the worm attacks in the Internet could be easily exploited to inject malicious codes into Wireless Sensor Networks (WSNs). Previous software-based remote code verification approaches such as SWATT and SCUBA have been shown difficult to deploy in recent work. In this paper, we propose and implement a remote attestation protocol for detecting unauthorized tampering in the application codes running on sensor nodes with the assistance of Trusted Platform Modules (TPMs), the tiny, cost-effective and tamper-proof cryptographic microcontrollers. In our design, each sensor node is equipped with a TPM and the firmware running on the node could be verified by the other sensor nodes in a WSN, including the sink. Specifically, we present a hardware-based remote attestation protocol, discuss the potential attacks an adversary could launch against the protocol, and provide comprehensive system performance results of the protocol in a multi-hop sensor network testbed.