An Improved Authentication & Key Exchange Protocol Based on ECDH for WSNs

Wide-spread use of wireless sensor networks (WSNs) that are consisted of resource-constrained sensor nodes in communication with gateways in sensitive and mission-critical industries have highlighted the need for a secure yet fast communication protocol between users, gateways and sensor nodes. Due to the properties of the network, elliptic-curve cryptography seems to be the most viable choice as it requires less resources than most other options. In this paper we analyze the protocol suggested by Moghadam et al. which is based on ECDH (elliptic-curve Diffie-Hellman) and mention some of the flaws in their proposed authentication and key exchange protocol. Some attacks are also mentioned to further explain the shortcomings of their schema. Then a modified version of the protocol is proposed, analyzed and checked against the same attacks as an informal security proof.