Sensor networks are ideal candidates for a wide range of applications such as critical infrastructure protection. It is necessary to guarantee the trustworthiness and resilience of sensor networks as well as the sensing applications, especially when the failure of these applications may result in catastrophic events with impacts affecting safety, security, the economy and society at large. The objective of this project is to develop practical techniques for building trustworthy and resilient sensor networks as well as instructional materials that facilitate the education of these techniques. The research activities are focused on practical broadcast authentication, trustworthy and resilient clock synchronization, and light-weight and collaborative intrusion detection in sensor networks. To handle the unique challenges (e.g., resource constraints, threat of node compromises) in sensor network security, this project seeks effective integration of cryptographic