UPPR: Universal Privacy-Preserving Revocation

Leandro Rometsch; Philipp-Florens Lehwalder; Anh-Tu Hoang; Dominik Kaaser; Stefan Schulte

Paper 2025/1919 Original: eprint.iacr.org/2025/1919 ↗

UPPR: Universal Privacy-Preserving Revocation

Leandro Rometsch

Philipp-Florens Lehwalder

Anh-Tu Hoang

Dominik Kaaser

Stefan Schulte

Abstract

Self-Sovereign Identity (SSI) frameworks enable individuals to receive and present digital credentials in a user-controlled way. Revocation mechanisms ensure that invalid or withdrawn credentials cannot be misused. These revocation mechanisms must be scalable (e.g., at national scale) and preserve core SSI principles such as privacy, user control, and interoperability. Achieving both is hard, and finding a suitable trade-off remains a key challenge in SSI research. This paper introduces UPPR, a revocation mechanism for One-Show Verifiable Credentials (oVCs) and unlinkable Anonymous Credentials (ACs). Revocations are managed using per-credential Verifiable Random Function (VRF) tokens, which are published in a Bloom filter cascade on a blockchain. Holders prove non-revocation via a VRF proof for oVCs or a single Zero-Knowledge Proof for ACs. The construction prevents revocation status tracking, allows holders to stay offline, and hides issuer revocation behavior. We analyze the privacy properties of UPPR and provide a prototype implementation on Ethereum. Our implementation enables off-chain verification at no cost. On-chain checks cost 0.56-0.84 USD, while issuers pay only 0.00002-0.00005 USD per credential to refresh the revocation state.

Metadata

Available format(s): PDF
Category: Cryptographic protocols
Publication info: Preprint.
History: 2026-01-06: last updated; 2025-10-14: published
Short URL: https://ia.cr/2025/1919
License: https://creativecommons.org/licenses/by/4.0/

BibTeX

@misc{cryptoeprint:2025/1919,
      author = {Leandro Rometsch and Philipp-Florens Lehwalder and Anh-Tu Hoang and Dominik Kaaser and Stefan Schulte},
      title = {UPPR: Universal Privacy-Preserving Revocation},
      howpublished = {Cryptology {ePrint} Archive, Paper 2025/1919},
      year = {2025},
      url = {https://eprint.iacr.org/2025/1919}
}