VeriPriv: a privacy preserving attribute verification protocol for decentralized authentication

Attribute-based verification becomes more and more popular compared with identity-based authentication from the privacy point of view. Users can be authenticated by pieces of attributes rather than the whole identity. Attribute-based anonymous credential systems enable a user to prove possession of a given set of attributes to a verifier, without revealing information about other attributes. However, the challenge lies in how to securely prove the possession of attributes. In our paper, we propose a decentralized zero-knowledge protocol for attribute verification. There are three attribute verification modes, namely 1-out-of-n, n-out-of-n, and the Combined Verification Mode. The first two modes represent the "OR" and "AND" gates, while the Combined Verification Mode supports an OR of non-empty groups of AND attributes. We prove the security properties of the protocol in the security analysis. Meanwhile, we also outline some of the use-cases and applications of the proposed protocol, such as Internet of Things(IoT), federated learning and data validation.