FINDING · DETECTION
Inter-arrival time sequences between client DoH/3 request packets retain site-specific temporal structure despite QUIC padding and stream multiplexing, exhibiting characteristic micro-burst and inter-burst gap patterns. Using timing features alone, LSTM achieves 83.75% ± 0.92% accuracy at 449 classes, and DoHFuse with its dual-branch DMAG-LSTM reaches 89.08% ± 0.49%, while length-only LSTM degrades to 8.95% under the same conditions.
From 2026-zhang-dohfuse-dual-branch-architecture — DoHFuse: A Dual-Branch Architecture with DMAGLSTM for Website Fingerprinting over DNS over HTTPS/3 · §IV.D; §V.B; §V.C; Table II · 2026 · arXiv preprint
Implications
- Adding inter-packet interval jitter (not just fixed padding) is critical: request-interval statistics and burst timing are the residual fingerprinting signal that survives EDNS(0) padding, so deliberate timing randomization must be layered on top of size obfuscation.
- Covert channels that batch or coalesce DNS queries to flatten burst–gap patterns would directly degrade the discriminative features exploited by DoHFuse's temporal branch.
Tags
Extracted by claude-sonnet-4-6 — review before relying.