Private Identity-Related Attribute Verification Protocol Using SoulBound Tokens and Zero-Knowledge Proofs

The need for self-sovereign and privacy-preserving identity solutions is becoming more critical, due to increasing concerns about privacy and data security, especially when it involves highly sensitive Personally Identifiable Information (PII). In this article we propose a protocol based on blockchain technology, Soulbound tokens (SBT) and zero-knowledge proofs (ZKP) to address these challenges. By using the public key of the identity holder address to encrypt the data, our protocol can represent various identity attributes while ensuring privacy. We explore the concepts of self-sovereign and privacy-preserving identity and discuss the advantages of using blockchain-based SBTs and ZKPs in identity verification systems. Moreover, this article provides an overview of the state of the art in privacy-preserving identity using SBTs and ZKPs within the blockchain ecosystem, highlighting the potential benefits and future directions for this emerging field.