Security and Deployment Issues in a Sensor Network

We are facing an growing demand in deploying large scale sensor networks in the real world. However, there are still many obstacles before we can proceed. Security is a major concern as we need to be sure that the data we receive is authentic and confidential, and have not been tampered with. This is especially difficult because sensors have very limited resources and we cannot guarantee physical security of the sensors. Limited bandwidth is another problem as we scale up the number of sensors. We need to ensure that we achieve fairness and do not starve any sensors. We present our design and implementation to address these issues, and describe our deployment of a real sensor network and the problems that we encountered. Our security protocol works well on sensors with 8KB of memory and 4MHz 8-bit Atmel processors. Our adaptive transmission scheme achieves fairness among sensors in the network and prevents starvation. We also implemented two applications: people tracking and light sensing.