Anderson establishes that anonymity and physical redundancy are substitutes: 'Anonymity enables us to reduce diversity.' Tamper-resistant hardware security modules controlling anonymized file servers ensure no identifiable group of people — including sysadmins — can locate or delete a specific file without breaking a quorum of hardware modules distributed across jurisdictions.

Using Byzantine-fault-tolerant protocols (specifically Rampart), seven replicas suffice to resist a conspiracy of any two malicious administrators or the accidental destruction of four systems with guaranteed complete recovery. Signing all files with a system key further ensures that a full recovery is possible as long as a single valid copy and an uncompromised public key survive.

§4.6 defense

Effective censorship of a distributed service requires simultaneous enforcement across every jurisdiction hosting nodes. With no head office to coerce, a legal attack requires coordination across multiple independent legal systems — making successful suppression 'very expensive indeed — hopefully beyond even the resources of governments.' Local bans (e.g., country-level) do not affect nodes in other jurisdictions.

§4.1–§4.2 policy

The Eternity Service's core design stores a file on 100 servers worldwide but retains records of only 10 for auditing, destroying the remaining 90 records. Even if a user is legally compelled to disclose all 10 known server locations and those copies are seized, 90 copies survive at unknown locations and can be retrieved via anonymous broadcast once the user leaves the jurisdiction.

§4.3 defense

Traffic analysis is identified as the primary threat to location secrecy in a distributed anonymous storage system: if an adversary can correlate inter-server communications or link requests to stored file locations, it can target physical seizure. The paper proposes mix-nets (Chaum 1981) for user-facing file delivery and dining-cryptographers ring protocols for inter-server communications, supplemented by traffic padding, so that even traffic analysis yields no actionable location information.

§4.5 detection

A three-stage detection pipeline exploiting the "dual-role" behavioral fingerprint of single-IP circumvention relays achieved 23.2% recall (96/414 ground-truth relays) with a 0.18% false-positive rate against 97,651 benign TLS servers, for an overall accuracy of 99.5%. The ground-truth set covered OpenVPN, WireGuard, and SOCKS relays identified in a 17 TB single-day backbone trace (WIDE Project, April 9, 2025).

2026-almutairi-server §3.4, Table 1 traffic-shapedpiflow-correlation

Multi-censor simulations show that single-censor-optimized distribution strategies perform suboptimally in realistic multi-region deployments. When two networks have different censor strategies (e.g., one optimal, one zig-zag), the distributor cannot detect that a proxy is blocked until all censors have blocked it; this leaves clients without reachable proxies despite the proxy appearing "available" from the distributor's view. The authors conclude that "single-censor evaluation does not accurately predict more realistic deployment performance." A zig-zag censor in one region with 0.25 weight caused 44.4% collateral damage while reducing proxy lifetime to a median of 4 steps.

2026-fares-game §6, Table 4 traffic-shapeflow-correlation

The zig-zag traffic analysis attack (confirmed supported in Geedge TSG leak) rapidly enumerates all static proxy pools. With ζ_watch ∈ {4, 6} steps and a best-quality classifier (ρ_TP=0.99, ρ_FP=0.001), almost total proxy enumeration and user blockage occurs well before step 300. Even ζ_watch=2 leaves ~50% of users blocked. Collateral damage is high across all settings when ζ_watch ≥ 4: eventually ~50% of innocent servers are also blocked. However, Snowflake-style ephemeral proxies resist zig-zag effectively: reachability remains above 95% after 360 steps because churn prevents the censor from expanding its known proxy set beyond agents' direct assignments.

2026-fares-game §5.1, Fig 3, Fig 4 traffic-shapeflow-correlation

The paper concludes with design guidelines for future FIA-based privacy-enhancing technologies, identifying that path-aware routing in SCION and NDN's in-network caching both create new surveillance exposure: SCION path headers reveal routing metadata to on-path censors; NDN caching at routers means content is replicated at points under censor control. The authors recommend that PETs built on FIAs treat these architectural features as threat vectors, not privacy benefits.

2025-wrana-sok-surveillance §6 dpiflow-correlation

Wrana et al. systematically assess how well existing surveillance and censorship mechanisms can target users of Future Internet Architectures (FIAs) — including NDN, SCION, XIA, and MobilityFirst — finding that DPI and flow-correlation techniques from the current internet map onto FIA traffic with moderate adaptation. The paper identifies that FIA naming/addressing schemes introduce new censorship attack surfaces (e.g., content-name-based filtering in NDN) not present in IP-based architectures.

2025-wrana-sok-surveillance §4, §5 dpiflow-correlationmeasurement-platform

Per-flow RTTdiff detection rates are only ~20% because the majority of proxy flows connect to CDN-cached content (Cloudflare, Google, Fastly) that sits within 5ms of the proxy, suppressing the discrepancy. However, aggregating across flows per website visit yields detection rates exceeding 70%—and from the abstract, approximately 80% of top-5K domains generate at least one detectable flow—with half of those detections made within the first 60 packets. This means an adversary can reliably expose client and proxy IPs after just a few website visits.

2025-xue-discriminative §VI-C-2, Table II traffic-shapeflow-correlation