FINDING · EVALUATION
IP-based fingerprints are operationally stable: approximately 60% of domains exhibit no IP changes across the three-month measurement period for both IPv4 and IPv6. Among churning domains, per-domain churn behavior is comparable across protocols—about 28% of churning IPv4 domains rotate within one hour on average vs 35% for IPv6. Fingerprint databases of ≈100 KB per site (50–60 GB for 520K sites) can be maintained with only periodic DNS re-resolution at negligible overhead for adversaries already collecting NetFlow data.
From 2026-ahmad-more-space-less — More Space, Less Privacy? Measuring the Effectiveness of IP-based Website Fingerprinting in IPv6 · §6.4, §5.3.2 · 2026 · PoPETs 2026
Implications
- The attack is operationally cheap and long-lived: a censor building an IP fingerprint database once can identify 60%+ of destinations for months without updating it, so defenses cannot rely on temporal decay alone.
- Circumvention tools serving long-lived sessions should consider periodic IP rotation on the server side (exploiting IPv6 address space abundance) as a structural defense, targeting the ~35% of IPv6 domains that already rotate sub-hourly naturally.
Tags
Extracted by claude-sonnet-4-6 — review before relying.