Authentication in Wireless Sensor Networks Using Dynamic Identity Based Signatures

A Wireless sensor network (WSN) is composed of a large number of sensor nodes, which perform multiple tasks, namely sensing, data processing and forwarding of observed data. WSNs nodes may possess sensitive data that are prone to various attacks. For such a network to be viable, integrity and authenticity should be provided to the data generated by the sensor nodes. For example, in military surveillance and enemy tracking applications, the localization system of the nodes is the target for many attackers. In such applications, the base station would broadcast the command for localization to all the sensor nodes in the field. The sensor nodes would respond to this query with the required data. Any compromised node at this point would generate false data and may lead to miscalculation of the localization process and incorrect decision making. Hence, a resilient authentication is necessary to authenticate a node. As a first step towards this objective, a lightweight identity based signature for authentication of the sensor nodes is proposed in this paper. The scheme uses “fingerprint”, i.e. a lifetime secure memory fraction in the sensor nodes as a parameter for signature generation. In addition, the parameters for fingerprints are generated dynamically and the computed fingerprint values are not stored permanently in the hardware. Because of these features, the sensor nodes can overcome identity based attack like Sybil attack. Also, it is impossible to read the contents of the sensor node even if the node is captured by the attacker. The security proof for this scheme is based on the Computational Diffie-Hellman assumption and proved in the random oracle model. On the computation point of view, the proposed scheme requires minimal operations in signing than the existing identity based signature approaches.