A Survey on Blockchain-Based Identity Management Systems for the Internet of Things

The Internet of Things aims at connecting everything ranging from individuals, organizations, companies to things in the physical and virtual world. The digital identity has always been considered as the keystone for all online services and the foundation for building security mechanisms such as authentication and authorization. However, current literature still lacks of a comprehensive research on the digital identity management for the Internet of Things (IoT). In this paper, we identify digital identity challenges and solutions for the Internet in general. We then focus on how existing solutions cope with IoT requirements such as scalability, interoperability, mobility, security and privacy. We also investigate recent surging blockchain sovereign identity solutions and enumerate some projects and startups which are focusing on IoT identity problems. Furthermore, we elaborate challenges of building identity management systems for the IoT, including access control, privacy preserving, trust and performance respectively. At last, we conclude with the promising future research trends in building IoT identity management systems.