Websites generating only one or two observable non-Google DNS queries per visit have classification accuracy below 30% in DoHFuse's closed-world evaluation, compared to the model's overall 88.05% on 449 classes. Sites such as ftc.gov and ailawandorder.com fell near zero accuracy, revealing that extremely sparse DNS activity is a natural but uncontrolled defense against timing-based fingerprinting.
From 2026-zhang-dohfuse-dual-branch-architecture — DoHFuse: A Dual-Branch Architecture with DMAGLSTM for Website Fingerprinting over DNS over HTTPS/3
· §V.D; Figure 7
· 2026
· arXiv preprint
Implications
Circumvention tools that generate cover traffic through DoH/3 should suppress or limit the total query count per session, mimicking low-activity sites to reduce per-session fingerprint distinctiveness.
Deliberately injecting decoy DNS queries to sites in the 'hard to classify' regime could confuse classifiers that rely on query-count and timing CV as discriminative statistics.