Blockchain-based Traceable Selective Disclosure Credentials for Self-Sovereign Identity

Digital identities and credentials are important for authentication and authorization. Most contemporary digital identity systems rely on a central service provider, which may lead to privacy and centralization issues, such as data lost and information misuse. To address the problems, selective disclosure approaches within the self-sovereign identity have been proposed. However, these approaches primarily focus on data minimization, often overlooking the need for presentation unlinkability and identity supervisibility. In this paper, we propose a blockchain-based selective disclosure approach that supports presentation unlinkability, attribute aggregation, and identity traceability. We implement our approach and evaluate its efficiency by comparing it with approaches including atomic credentials, hashed values and selective disclosure signatures. The results demonstrate that our approach successfully achieves all intended objectives with high efficiency, rendering it applicable to realistic scenarios such as cross-chain authentication and access control in IoT.