Blockchain-Based Self Sovereign Identity Systems: High-Level Processing and a Challenges-Based Comparative Analysis

Traditional identity management systems trust centralized certification authorities (CAs) to manage public keys and authenticate the mapping between users and their respective keys. This presents several security concerns as a CA is a single point of failure in the system. Besides, managing public keys by a centralized CA is becoming costly regarding the current growth in users and the distributed systems they use. Also, centralized identity management systems lack interoperability and present privacy concerns. Self-Sovereign Identity (SSI) systems aim to address these issues by providing decentralized identity ecosystems that facilitate the registration and exchange of identity attributes, and the propagation of trust between participating entities, without needing to rely on a central authority. Blockchain technologies improve security in the SSI systems by allowing control of the storage and disclosure of credentials and identity information. They improve the integrity, confidentiality, and interoperability of users’ information. This paper highlights the challenges that an Identity Management System (IdM) must overcome, and how blockchain-based IdMs leverage blockchain technology to meet these challenges. It also presents a comparative analysis of three SSI ecosystems based on the above-mentioned challenges. An SSI layered architecture model detailing the actors, objects, components, and processes is then proposed.