FINDING · EVALUATION
Packet-level classification without flow context is significantly harder for self-supervised models: on CSTNET packet-level evaluation, shallow learning achieves 63.73% Macro-F1 while AlignTraffic reaches only 24.97%, because individual encrypted-payload packets carry minimal application-identifying information once the initial handshake is excluded.
From 2026-liu-understanding-self-supervised-representation — Understanding Self-Supervised Representation Learning for Encrypted Traffic · §VI.B, Table XI · 2026 · arXiv preprint
Implications
- Censors benefit primarily from capturing and analyzing the initial handshake packets; circumvention protocols that delay or suppress application-identifying plaintext until after connection establishment reduce the early-decision window available to flow classifiers.
- Per-packet classification without handshake context is unreliable for ML models (~25% Macro-F1) but explicit protocol feature extractors remain effective (~64%); protocols must eliminate both handshake plaintext and observable TLS record-header structure to defeat both classifier families.
Tags
Extracted by claude-sonnet-4-6 — review before relying.