MoDID: Decentralized Identity Management for Multiple Owners

Identity management plays a critical role in Web3 applications. Decentralized Identity (DID) offers a privacy-preserving solution, giving users full control over their identity information. Existing research on DID primarily focuses on single-owner scenarios, where owners have complete privileges for owner management and credentials. However, in multi-owner cases, current coarse-grained identity management approaches lead to serious privacy and security problems, such as identity impersonation and high key recovery overhead. Little work has been done on identity management for multiple owners. In this paper, we propose MoDID, a fine-grained identity management scheme for multiple owners, which complies with the DID standard proposed by W3C. First, our solution allows multiple owners to control DID subjects flexibly and reliably through hierarchical owner management. Additionally, we design a secure key recovery scheme to reduce the risk of identity loss while introducing lower overhead. Finally, we implement MoDID on the Sepolia Ethereum Test Network to evaluate the effectiveness of our proposed scheme. The result demonstrates that our system allows multiple owners to manage a single identity with lower gas consumption and time consumption than the state-of-the-art.