zkDaily - 2026-05-19

零知识证明 zkDaily

ZKP Frontier Tracker 🎯

Tue

05.19

2026

Attribute-Based Threshold Issuance Anonymous Counting Tokens and Its Application to Sybil-Resistant Self-Sovereign Identity

Paper

https://cic.iacr.org/p/3/1/19

Behzad Abdolmaleki Unlinkability

Abdolmaleki et al. propose tACT, a publicly verifiable threshold anonymous counting token in a distributed-trust setting, and use it to build a Sybil-resistant SSI system with threshold issuance, unlinkable multi-show selective disclosure, improving over CanDID.

Notes

tACT is the first publicly verifiable threshold anonymous counting token in a distributed-trust setting.
The proposed SSI system features non-interactive, non-transferable credentials with minimal user-issuer interaction.
Formalizes strong unlinkability security model, ensuring privacy even under issuer-verifier collusion.
Benchmark results show improved efficiency over CanDID while supporting more issuers.
Techniques involve bilinear maps, zero-knowledge proofs, and threshold cryptography.

Collected by @icerdesign

零知识证明 zkDaily

Q&A Deep Dive 💬

Tue

05.19

2026

What are Self-Sovereign Identity (SSI) and Sybil-resistant SSI systems?

SSI is a digital identity system where users control their own identity data, supporting privacy and selective disclosure. A Sybil-resistant SSI system further prevents users from creating many fake identities while preserving anonymity and unlinkability.

How does this work improve over CanDID?

The scheme achieves strong unlinkability, reduces repeated user-issuer interactions, and supports one-round parallel threshold issuance.

What is strong unlinkability?

Strong unlinkability means that even if issuers and verifiers collude, they still cannot link multiple credential uses to the same user.

Prompted by @icerdesign