In the open-world 5-tab setting — where each trace contains one unmonitored site, substantially increasing noise and class imbalance — DEMUX achieves AUC of 0.998, P@5 of 0.951, and MAP@5 of 0.966, while ARES'25 achieves 0.988/0.869/0.911. DEMUX's advantage widens in the open-world setting (the P@5 gap grows from 2.6 pp to 8.2 pp versus closed-world), confirming that state-of-the-art WF attacks are not defeated by open-world conditions or unmonitored co-browsing traffic.
From 2026-yuan-demux-boundary-aware-multi-scale — DEMUX: Boundary-Aware Multi-Scale Traffic Demixing for Multi-Tab Website Fingerprinting
· §V-C, Table III
· 2026
· arXiv preprint
Implications
Including unmonitored 'cover' traffic by browsing non-targeted sites concurrently does not meaningfully protect against DEMUX-class WF attacks — circumvention tools cannot rely on decoy traffic patterns to defeat fingerprinting.
Effective defenses must alter the statistical properties of the encrypted traffic stream itself (padding, rate shaping, splitting) rather than depending on realistic-looking co-browsing activity to confuse classifiers.