Zero-Knowledge Proofs in Decentralized Identity Systems: Privacy, Interoperability, and Cross-Border Regulatory Compliance

Abstract

Decentralized Identity (DID) and Self-Sovereign Identity (SSI) frameworks aim to restore user agency over digital attestations by disintermediating centralized identity providers. However, naive implementations of decentralized identity inherit substantial privacy risks, such as persistent identifier correlation, metadata leakage, and cryptographic signature tracking across verifiers. Zero-Knowledge Proofs (ZKPs) have emerged as the foundational cryptographic primitive capable of reconciling this tension by enabling verifiable attestations without revealing underlying claims or cryptographic artifacts. This comprehensive review examines the integration of modern ZKP constructions—including zk-SNARKs, zk-STARKs, and multi-message signature schemes (BBS/BBS+)—within decentralized identity ecosystems.