DiStefano: Decentralized Infrastructure for Sharing Trusted Encrypted Facts and Nothing More
Sofía Celi (Brave Software), Alex Davidson (Universidade NOVA de Lisboa, NOVA LINCS), Hamed Haddadi (Brave Software, Imperial College London), Gonçalo Pestana (Hashmatter), Joe Rowell (Royal Holloway, University of London) | Security, Cryptography
We design DiStefano: an efficient, maliciously-secure framework for generating private commitments over TLS-encrypted web traffic, for a designated third-party. DiStefano provides many improvements over previous TLS commitment systems, including: a modular protocol specific to TLS 1.3, support for arbitrary verifiable claims over encrypted data, inherent ring privacy for client browsing history, and various optimisations to ensure fast online performance of the TLS 1.3 session. We build a permissive open-source implementation of DiStefano integrated into the BoringSSL cryptographic library (used by Chromium-based Internet browsers). We show that DiStefano is practical for committing to facts in arbitrary TLS traffic, requiring < 1s and <= 5KB to execute the online phase in a LAN setting.
