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Crescent and Longfellow (eid-privacy, 2025)

URL: https://eid-privacy.github.io/wp0/2025/11/28/crescent-longfellow-showdown.html

Summary

Side-by-side comparison of Microsoft Crescent and Google Longfellow as candidate ZKP systems for privacy-preserving e-ID credentials. Covers architecture, performance benchmarks (Crescent: ~1 s online after 20 s pre-computation; Longfellow: 1.17 s prover / 0.68 s verifier on Pixel 6 Pro, ~300 KB proof), setup requirements, post-quantum posture, and suitability for Swiss e-ID (Swiyu) deployment. Crescent relies on a trusted setup (Groth16) but has a smaller online proof; Longfellow is transparent and post-quantum safe but larger.

Related resources

• Anonymous Credentials from ECDSA (Frigo & shelat 2024) (paper, 2024)
• Crescent: Stronger Privacy for Existing Credentials (Paquin, Policharla, Zaverucha 2024) (paper, 2024)
• Secure and Privacy-Preserving Credentials for E-ID Proof-of-Concept (Gasser, Humbert, Elghareeb 2025) (paper, 2025)