Protozoa successfully bypassed censorship in China, Russia, and India using whereby.com as a carrier. Despite several WebRTC services being blocked in China (appr.tc, discordapp.com, hangouts.google.com, messenger.com), at least seven alternatives remained reachable (aws.amazon.com/chime, coderpad.io, gotomeeting.com, slack.com, whereby.com, and others), ensuring carrier availability. Covert sessions over the alternative services coderpad.io and appr.tc achieved AUCs of 0.58 and 0.60, respectively, and average throughput of 1388–1420 Kbps.

Protozoa's encoded media tunneling embeds covert IP packets directly into VP8-encoded frame bitstream partitions (EFBP) after lossy compression, rather than into raw pixel data. Because SRTP uses a stream cipher that preserves plaintext size, overwriting EFBP bits leaves encrypted packet sizes identical to legitimate sessions, and the covert channel achieves 98.8% utilization of available frame space at an average throughput of 1422 Kbps—a 3× improvement over Facet and roughly three orders of magnitude over DeltaShaper's 7 Kbps maximum.

§4.4, §6.2 defense

Protozoa's encoded media tunneling achieves an AUC of 0.59 against a state-of-the-art ML traffic classifier using packet-size and inter-arrival-time features—near the 0.5 random-guessing baseline—compared to >99% detection rates for prior tools such as Facet and DeltaShaper. To block 80% of Protozoa flows (TPR=0.8), a censor would erroneously flag approximately 60% of legitimate WebRTC flows (FPR=0.6). This resistance holds across trace durations from 10–60 seconds (AUC range 0.56–0.61) and across RTT, bandwidth, and packet-loss variations.

§6.2, Table 1, Figure 8 evaluation

Protozoa's covert channel throughput degrades gracefully under bandwidth constraints but remains usable for common applications: average throughput is 975 Kbps at 1500 Kbps cap, 460 Kbps at 750 Kbps, and 91 Kbps at 250 Kbps. Under 2% and 5% packet loss the channel sustains 1130 Kbps and 360 Kbps, respectively, while 10% loss (near WebRTC tear-down threshold) still yields 160 Kbps without breaking the connection. Traffic analysis resistance is preserved across all these conditions, with AUC peaking at 0.65.

§6.3, Figures 9–10 evaluation

Protozoa uses the economic and social indispensability of popular WebRTC conferencing services as a censorship deterrent: blocking all WebRTC traffic imposes prohibitive collateral damage on legitimate commerce and communication. This 'parasitism' strategy means the circumvention tool inherits the blocking immunity of the carrier without requiring any protocol mimicry at the network level. Protozoa requires only one reachable WebRTC service to function, and Table 3 confirms at least five services remained unblocked in China during testing.

§3, §7.2 defense

The June 2025 Iran shutdown—carried out during the Iran-Israel war beginning ~June 19—did not use BGP route withdrawals as in 2019. Instead, authorities applied service-level restrictions at the national border: DNS poisoning of foreign destinations, protocol whitelisting permitting only pre-approved domestic services, and DPI to block circumvention-tool traffic. Iran's international traffic fell roughly 90% while the country's BGP routes remained advertised, making the shutdown invisible to BGP-based monitoring systems. OONI measurement volume, which totalled 121,333 in June 2025, collapsed to under 200 submissions on June 19-20.

2025-iran-shutdown-measurement Executive Summary / §2 dpidns-poisoningport-blockingip-blocking

Article 19 documents that Iran's National Information Network (NIN / SHOMA) was designed with explicit reference to China's Great Firewall as a model, with institutional mirroring: Iran's Supreme Council of Cyberspace parallels China's Cyberspace Administration of China, and both governments share a "cyber sovereignty" doctrine used to justify domestic content controls and cross-border technology transfer. The report frames Iran's filtering infrastructure as deliberately architected to replicate GFW capabilities, not as an independently developed system.

2026-article19-tightening-the-net §2, §3 dpisni-blockingdns-poisoningip-blockingbgp-hijackthrottling

The GNL reveals that Geedge actively maintains dedicated VPN-infrastructure tracking datasets. The China-specific component includes 7,016 domains in a "vpn-finder-plugins" repository (mesalab_git/intelligence-learning-engine), 4,810 NordVPN server domains, and a Pakistan-specific file listing 68 Psiphon CDN domains (geedge_docs/TSGEN/.../Psiphon-CDN_20240430.json) dated April 2024. A Myanmar deployment file (M22-VPN List.html, 27 domains) further confirms country-specific VPN blocklists are operationally maintained. The "Appsketch" program reverse-engineers VPN apps to extract domains and IP addresses for blocking.

2026-sheffey-geedge §4.2, Table 3 dpisni-blockingip-blocking

Iran's censorship of refraction-networking proxies (Conjure via Psiphon) is not monolithic: different ISPs independently deploy different techniques and timelines. Over 800 million logged Conjure connections from July 2023–February 2025 across 10+ Iranian ASes show TCI (AS58224, ~33% of traffic) uses packet injection, while MCCI/Hamrah-e Avval (AS197207, ~22%) applies IP-based blocking, and some ASes (Parsonline AS16322, Shatel AS31549) show no proxy blocking at all.

2025-alaraj-iran-refraction §4 rst-injectionip-blockingpacket-injectiondpi

Amnesty International's 102-page investigation identifies a multi-vendor surveillance stack deployed in Pakistan: Chinese DPI (Geedge/MESA-derived), Canadian social-media monitoring (Netsweeper), and Emirati commercial spyware (Pegasus and FinFisher). The system enables deep packet inspection, SNI-based filtering, and traffic-shape classification at national scale, including targeted interception of encrypted messaging apps and VPN traffic.

2025-amnesty-pakistan-shadows §3, §5 dpisni-blockingip-blockingtraffic-shapeml-classifier

InterSecLab's 76-page analysis of the Geedge/MESA leak (based on nine months of indexing and translating >100,000 documents) characterizes the Tiangou Secure Gateway (TSG) product line as a commercially deployable detection stack that combines deep packet inspection, real-time mobile subscriber monitoring, active probing, ML-based traffic classifiers, and granular per-region rule sets. TSG is not a research prototype — leaked documentation includes deployment timelines and client government interactions for Kazakhstan, Ethiopia, Pakistan, Myanmar, and one unnamed country, with censorship rules explicitly tailored to each region.

2025-interseclab-internet-coup §3–§5 (InterSecLab report) dpiactive-probingml-classifiersni-blockingip-blockingtraffic-shapefully-encrypted-detect