SensorTrust: A Resilient Trust Model for Wireless Sensing Systems ✩ Guoxing Zhan a , Weisong Shi a , Julia Deng b a Department of Computer Science, Wayne State University 5143 Cass Avenue, Detroit, MI 48202, USA b Intelligent Automation Inc., 15400 Calhoun, Rockville, MD 20855, USA Abstract Wireless sensor networks (WSNs) are prone to failures and malicious at- tacks. Traditional approaches from encryption and authentication are not sufficient to solve the problems. Trust management of WSNs is bringing new approaches. However, it is still a challenge to establish a trust environment for WSNs. To conquer that challenge, we propose a resilient trust model with a focus on data integrity, SensorTrust, for hierarchical WSNs. SensorTrust integrates past history and recent risk to accurately identify the current trust level. It employs Gaussian model to rate data integrity in a fine-grained style and a flexible update protocol to adapt to varied context. With acceptable overhead, SensorTrust proves resilient against varied faults and attacks. Keywords: Wireless Sensing Systems, Sensing Data, Trust Model 1. Introduction Wireless sensor networks (WSNs) are prone to failures and malicious at- tacks. In addition to unstable radio communication, data integrity is also an important issue. Though a secure and robust routing layer may enhance the data delivery ratio, a compromised node itself could report inaccurate or even forged data. Meanwhile, constrained by WSNs resource-starving nature in ✩ A poster abstract of this work was presented at ACM SenSys 2009. ✩✩ This work is in part supported by the National Science Foundation grant CNS- 0721456. Email addresses: gxzhan@wayne.edu (Guoxing Zhan), weisong@wayne.edu (Weisong Shi), hdeng@i-a-i.com (Julia Deng) Preprint submitted to Pervasive Computing October 17, 2010