FINDING · DETECTION
CipherSight achieves 91.09% accuracy in Singapore and 90.59% in France when trained exclusively on US traffic, with only 0.50 pp variation between regions; the strongest regional baselines lag by 11.56 pp (Singapore) and 8.52 pp (France), and some baselines vary by up to 24.38 pp across regions, confirming that TLS-record-level fingerprinting is geographically transferable while packet-level methods are not.
From 2026-song-ciphersight-robust-website — CipherSight: Robust Website Fingerprinting via Record-Resource Semantic Supervision under Distribution Shifts · Table 3, Geographic Drift · 2026 · arXiv preprint
Implications
- A censor can train on domestic traffic captures and apply the resulting classifier to users in other regions with minimal accuracy loss; geographically distributed circumvention infrastructure does not inherently evade fingerprinting.
- Defenses that rely on regional CDN or routing path variation to produce unpredictable traffic patterns are insufficient against TLS-record-level classifiers.
Tags
Extracted by claude-sonnet-4-6 — review before relying.