Wireless Sensor Networks (WSNs) are systems that may contain hundreds to thousands of low-power and low-cost
sensor nodes. The potential applicability of such systems is enormous; security surveillance and intrusion detection
systems for smart buildings and military bases, monitoring chemical plants for safety, wireless body area networks for
first responders, and monitoring habitats and natural environments for scientific and other purposes, among others. As
sensor network technology matures, we expect to witness an increasing number of such systems deployed in the real
world. This renders sensor networks more accessible to a wide variety of possible attacks and functional faults, as they
are deployed in remote, un-trusted, hostile environments. While different basic cryptographic building blocks and
hardened hardware architectures for most sensor network platforms are currently available and allow for protection on a
single sensor node basis, such building blocks are not effective in preventing wider scale attacks once a node has been
compromised. To this end, UtopiaCompression is proposing Proactive Trust Management System (PTMS) for WSNs.
Our solution is based on an easily extensible framework, tailored to deal with the resource constrained WSNs, and uses a
combination of novel outlier detection mechanisms and trust management algorithms to effectively cope with common
sensor faults and network attack models. Moreover, our solution is based on distributed in-network processing, which
significantly improves scalability and extends life time of the system. This paper also discusses the implementation and
evaluation of our solution on Sun SPOT sensors.