Distributed key agreement for group communications based on elliptic curves. An application to sensor networks

Internet of Things is built on sensor networks, which are enabling a new variety of solutions for applications in several fields (defense, health, and industry). Wireless communications are key for taking full advantage of sensor networks but implies new challenges in the security and privacy of communications. Security in wireless sensor networks is a major challenge for extending its applications. Moreover, the restrictive processing capabilities of sensor nodes have made the encryption techniques devised for conventional networks not feasible. In such setting, symmetric-key ciphers are preferred for key management in wireless sensor network; key distribution is therefore an issue solved by means of the protocols presented in this paper. Diffie–Hellman protocol (since its development) has been in the most important cryptographic primitive being the base for plenty of security protocols. In this paper, we proposed three key exchange protocols derived from the Diffie–Hellman method, applied to elliptic curves, named ECGDH-1, ECGDH-2, and ECGDH-3. Each performs secure key distribution sharing a group key among different nodes optimizing different network parameters. The security of the methods is based upon the difficulty of solving the discrete logarithm problem on elliptic curves. Making its application feasible to restrictive environments. Copyright © 2015 John Wiley & Sons, Ltd.