Decentralized and Self-Sovereign Identity in the Era of Blockchain: A Survey

With the emergence of concepts such as Metaverse and Web 3.0, digital identity plays a very important role as one of its infrastructures. The traditional digital identity model is no longer suitable for the requirements of the digital economy to some extent at this stage. The traditional centralized identity management system has many drawbacks. For example, the owner of the digital identity does not actually control his own identity, and there is a risk of easy disclosure and theft of identity information. Blockchain technology has the characteristics of decentralization, tamper-proof, traceability, etc., which can effectively solve the problems of centralized digital identity. After analyzing and summarizing the evolution trend of digital identity from centralization to decentralization, this paper focuses on the Self-Sovereign Identity (SSI) based on blockchain. Based on the analysis and comparison of various SSI implementation schemes, the development difficulties of blockchain digital identity are summarized and the future development direction is pointed out.