SEKM-IoT: Secure and Efficient Key Management for Dynamic Access Control in Smart IoT Systems

In this paper, we focus on the critical challenge of establishing a secure and efficient key management scheme that enables dynamic access control in hierarchical Internet of Things (IoT) systems, particularly linear hierarchies with multiple classes. In the proposed scheme, denoted SEKM-IoT, a key graph technique is used to effectively update class keys when membership changes occur. Moreover, a secure key derivation technique is employed to allow members of higher classes deriving class keys of the lower ones using a one-way hash function. Security analysis shows that SEKM-IoT ensures forward secrecy, backward secrecy, collusion freedom, and resistance against contrary attacks. Furthermore, performance analysis demonstrates that our scheme is lightweight, scalable, and incurs low cost in terms of storage, communication, and computation overheads.