An Efficient Group Key Agreement Scheme in IoT

In complex Internet of Things (IoT) network, lightweight group key agreement is of great interest because of the limited device resources. However, it is difficult for most schemes to efficiently cope with frequent membership changes. In this paper, we integrate Shamir secret sharing and Elliptic Curve Cryptography (ECC), innovatively propose both a predistribution strategy and a subgroup reduction secret rule, and subsequently design a novel group key agreement scheme with high dynamics and high security. Comparative analysis has shown that the benefits of the programme are as follows: 1) it is more suitable for resource-constrained terminals in dynamic environments, where member joining has a computational complexity of only $O(t)$ ($\mathbf{t}$ is the threshold) and leaving only require $O(1); 2$) it has multiple security attributes, especially resistant to replay attacks and man-in-the-middle tampering; 3) the overall computational complexity of the programme is only $O(\mathrm{n})$ (n is the number of group users), it’s more efficient than related schemes.