A Survey on Credential Revocation and DID Deactivation in Self-Sovereign Identity Systems

Self-Sovereign Identity (SSI) enables user-controlled identity management based on Decentralized Identifiers (DIDs) and Verifiable Credentials (VCs). However, ensuring reliable and privacy-preserving revocation remains one of the most critical and challenging aspects of credential lifecycle governance. This survey provides a narrative review of revocation mechanisms in SSI systems, spanning status-list approaches, cryptographic accumulators, positive-confirmation models such as short-lived credentials, and DID deactivation and governance-aware methods. Each category is analyzed across security, privacy, performance, scalability, and operational integration criteria, revealing their practical trade-offs. Based on an extensive analysis of academic sources, standards, and real deployments, the survey develops a unified taxonomy of SSI revocation and identifies persistent challenges: particularly privacy–accountability balancing, offline verification, key compromise handling, post-quantum readiness, and regulatory compliance. The findings offer guidance for system architects, implementers, and policymakers seeking trustworthy and interoperable revocation solutions in decentralized identity ecosystems.