Practical Identity-Based Key Agreement For Secure Communication in Sensor Networks

Despite much research effort key distribution in Wireless Sensor Networks (WSNs) still remains an open problem. In this paper we address this issue by proposing a simple identity- based key agreement scheme. Our protocol uses Identity-Based Cryptography (IBC) and secret key pre-distribution. We argue that IBC is in many ways a perfect solution for WSNs. It reduces the number of required keys, simplifying the key management in the network, and has a lower communications overhead than traditional public key protocols. We evaluate our proposal on a broad range of sensor platforms to show its efficiency on different CPU architectures. A complete key agreement procedure takes less than 3s on a resource- constrained Tmote Sky node without requiring any communication between two parties. To our knowledge this work is the first practical implementation of a complete IBC scheme on sensor devices. We identify a range of WSN applications which would benefit from the incorporation of a security architecture, and show that the scheme described here makes it feasible to deploy these applications in the real world.