All news with #anonymous credentials tag

Anonymous Credentials for Privacy-preserving Rate Limiting

🔐 Cloudflare presents a privacy-first approach to rate-limiting AI agents using anonymous credentials. The post explains how schemes such as ARC and ACT extend the Privacy Pass model by enabling late origin-binding, multi-show tokens, and stateful counters so origins can enforce limits or revoke abusive actors without identifying users. It outlines the cryptographic building blocks—algebraic MACs and zero-knowledge proofs—compares performance against Blind RSA and VOPRF, and demonstrates an MCP-integrated demo showing issuance and redemption flows for agent tooling.

Policy, Privacy, and Post-Quantum Anonymous Credentials

🔒 Lena Heimberger examines the challenge of building post-quantum Anonymous Credentials that are practical for large-scale use. The post summarizes real-world needs — from the EU digital identity wallet to Cloudflare’s Privacy Pass rate-limiting — and defines key requirements like unlinkability, unforgeability, round-optimality, and per-origin rate limits. It surveys PQ approaches (generic ZKP composition, lattice-based signatures, hash-and-sign with aborts, and MPC-in-the-head/VOLEitH), evaluates trade-offs in bandwidth and latency, and calls for standardized ZK-friendly hashes and PQ-native protocol designs.