BDIM: A Blockchain-Based Decentralized Identity Management Scheme for Large Scale Internet of Things

In large-scale Internet of Things (IoT) systems, centralized authentication can be challenging, for example in terms of identity management, authentication overhead, and single point of failure. Distributed identity management has been envisioned as a promising approach for mitigating above all, but the security and performance of the overall solution have not been extensively evaluated. In this article, we proposed a decentralized identity management scheme based on blockchain for tackling large-scale IoT such as VANET. We implement smart contracts to support large-scale user access control, together with design trust management methods for reputation evaluation and credit penalty mechanisms, which can prevent various types of attacks in distributed identification contexts. The experiment results and analysis justified that our scheme is scalable with good performance. Specifically, the system response is on a millisecond scale and all the functions consume within 250 ms. Also, the time consumption of the query maintains a manageable delay within 0.5 ms no matter the remarkable growth of users. Finally, we observe that the throughput of the current blockchain platform could meet the requirement of our scheme with the increasing number of users' upload request in real-world simulation.