Logo
ScienceStack
Table of Contents
Fetching ...
Sign In

SD-BLS: Privacy Preserving Selective Disclosure of Verifiable Credentials with Unlinkable Threshold Revocation

Denis Roio, Rebecca Selvaggini, Gabriele Bellini, Andrea D'Intino

TL;DR

SD-BLS tackles privacy-preserving selective disclosure and unlinkable threshold revocation for verifiable credentials by leveraging BLS signatures on the BLS12-381 curve and a threshold revocation workflow via PVSS. The approach enables proofs of possession for selected credentials without revealing their content, while enabling anonymous revocation that is verifiable by anyone and governed by a multi-stakeholder revocation dealer. It demonstrates fast revocation checks and provides concrete use-cases across digital identity, academia, KYC/AML, and blockchain VC contexts, with a practical benchmark and implementation in Zenroom. The work also discusses security considerations and future directions, including standards alignment with EUDI-ARF and potential integrations with Signroom, DIDroom, DPP, and DAO technologies for broader adoption.

Abstract

Ensuring privacy and protection from issuer corruption in digital identity systems is crucial. We propose a method for selective disclosure and privacy-preserving revocation of digital credentials using second-order Elliptic Curves and Boneh-Lynn-Shacham (BLS) signatures. We make holders able to present proofs of possession of selected credentials without disclosing them, and we protect their presentations from replay attacks. Revocations may be distributed among multiple revocation issuers using publicly verifiable secret sharing (PVSS) and activated only by configurable consensus, ensuring robust protection against issuer corruption. Our system's unique design enables extremely fast revocation checks, even with large revocation lists, leveraging optimized hash map lookups.

SD-BLS: Privacy Preserving Selective Disclosure of Verifiable Credentials with Unlinkable Threshold Revocation

TL;DR

SD-BLS tackles privacy-preserving selective disclosure and unlinkable threshold revocation for verifiable credentials by leveraging BLS signatures on the BLS12-381 curve and a threshold revocation workflow via PVSS. The approach enables proofs of possession for selected credentials without revealing their content, while enabling anonymous revocation that is verifiable by anyone and governed by a multi-stakeholder revocation dealer. It demonstrates fast revocation checks and provides concrete use-cases across digital identity, academia, KYC/AML, and blockchain VC contexts, with a practical benchmark and implementation in Zenroom. The work also discusses security considerations and future directions, including standards alignment with EUDI-ARF and potential integrations with Signroom, DIDroom, DPP, and DAO technologies for broader adoption.

Abstract

Ensuring privacy and protection from issuer corruption in digital identity systems is crucial. We propose a method for selective disclosure and privacy-preserving revocation of digital credentials using second-order Elliptic Curves and Boneh-Lynn-Shacham (BLS) signatures. We make holders able to present proofs of possession of selected credentials without disclosing them, and we protect their presentations from replay attacks. Revocations may be distributed among multiple revocation issuers using publicly verifiable secret sharing (PVSS) and activated only by configurable consensus, ensuring robust protection against issuer corruption. Our system's unique design enables extremely fast revocation checks, even with large revocation lists, leveraging optimized hash map lookups.
Paper Structure (39 sections, 11 equations, 4 figures, 1 table)

This paper contains 39 sections, 11 equations, 4 figures, 1 table.

Table of Contents

  1. Introduction
  2. State of the art
  3. Threats considered
  4. Linkability
  5. Privacy breach of revocation lists
  6. Revocation issuer corruption
  7. Overview
  8. Feature Comparison
  9. Key contributions
  10. Selective disclosure
  11. Anonymous cryptographic revocation
  12. Multi-stakeholder governance of revocations
  13. Fast revocation checks
  14. Applications
  15. Digital identity
  16. ...and 24 more sections

Figures (4)

  • Figure 1: Speed comparison of issue and verify in SD-BLS
  • Figure 2: Speed comparison of issue and verify in BBS+
  • Figure 3: Speed of verification of a claim over multiple revocations
  • Figure 4: Speed of creation and reconstruction of shares among multiple peers