FINDING · DETECTION
Under controlled lab conditions, a CNN trained on packet metadata (ports, sizes, TCP sequence numbers) achieved 99.5% accuracy classifying I2P packets with the 'Without payload' variant, versus only 72.5–76.5% using encrypted payload alone. However, when applied to the full recorded dataset, the 'Without payload' model's accuracy for the dominant irrelevant-traffic class dropped to 95.17% while maintaining 100% on target-class packets — but with a high false-positive rate making it forensically unreliable.
From 2026-rohrer-convolutional-neural-networks-deanonymisation-i2p — Convolutional-Neural-Networks for Deanonymisation of I2P Traffic · §V Second Experiment / Table IV–V · 2026 · arXiv preprint
Implications
- Metadata (packet sizes, port numbers, TCP sequence fields) leaks more classification signal than encrypted payloads; circumvention protocols must randomize or normalize these metadata fields, not just encrypt content.
- Dropping tcp_ack and tcp_seq simultaneously reduced CNN accuracy to 69.33% (Table VI), suggesting that stripping or randomizing TCP sequence numbers is a high-leverage defensive measure against metadata classifiers.
Tags
Extracted by claude-sonnet-4-6 — review before relying.