Blockchain-Based Verifiable Decentralized Identities for Cyber-Physical Web 3.0

The Internet environment and activities with large volume and variety of data have put forward higher requirements for the proof and verification of identity information. Achieving decentralized digital identity management helps to improve the performance of relevant proofs and authentication. The Decentralized Identity (DID) system is the link between the real and the virtual, giving physical entities digital identities that enable them to participate in Internet activities. However, faced with the huge number of entities accessing the DID system, the number of DID documents in the system has proliferated. It is still a big challenge to improve the scalability of the system while ensuring the efficiency of information access and verification. In this paper, we propose a blockchain-based verifiable decentralized identity system for cyber-physical web 3.0. First, we propose a blockchain-based system architecture with a specially designed storage structure for DID documents. Specifically, we design a structure based on Merkle Tree that visually summarises the physical associations of entities and reduces access overhead. Second, we design a verification scheme that enables users to verify the integrity of the identity data of the proof provider. We implemented the system framework and conducted experiments to evaluate the performance of our system. The experimental results proved the effectiveness of the system.