The post-quantum future of web privacy

Cloudflare explains how Privacy Pass, which relies on classical cryptography like RSA and elliptic curves, will need post-quantum replacements, and explores MOLE (Moderation Of unLinkable Endorsements), a design whose endorsements hide the issuer's identity. The post describes how the VOLE-in-the-Head proof system combined with multivariate signatures such as UOV and MAYO yields blind signatures like PoMFRIT (6.7KB, reducible to about 4.3KB with UOV), and how these building blocks can be reconfigured into MOLE endorsements and credentials. It also covers optimizations (fewer hashes, TurboSHAKE, smaller Keccak state, multivariate commitments and PRGs) and notes that multivariate cryptanalysis is still immature, so parameter changes and further study are expected.