sa   Saudi Arabia

DNEye detected DoTH (DoT and DoH) blocking across the largest number of ASes in China, with interference against Cloudflare, Quad9, AdGuard, and CleanBrowsing resolvers emerging in early March 2021. Blocking patterns varied per-AS rather than following a centralized GFW DNS-level policy, indicating individual ISP implementation. Saudi Arabia, by contrast, showed coordinated SNI-based blocking of the same DoH resolvers across different ASes, indicating centralized policy.

2022-hoang-measuring §4.2, Table 5 detection

Internet-wide IPv4 scanning found 386,187 IP addresses yielding amplification factors ≥ 100× via TCP middlebox reflection, with 82.9% of responses from the top 1 million IPs confirmed as originating from on-path middleboxes rather than endpoints. Nation-state censorship infrastructure dominates: China's GFW alone accounts for approximately 154 million responding IP addresses sharing a 3× RST+ACK (54 bytes each) fingerprint.

2021-bock-weaponizing §5.3, §5.5, Table 4 evaluation

Nation-state censors produce characteristic TCP response fingerprints: China's GFW sends 3× RST+ACK (54 bytes each) from ~170 million IPs; Iran's infrastructure sends 402–405-byte FIN+PSH+ACK plus 54-byte RST+PSH+ACK from 8.6 million IPs (75.7% of responsive Iranian addresses); Saudi Arabia sends a 97-byte PSH+ACK plus 2× 1,354-byte PSH+ACKs at 18.9× amplification from 400,000+ IPs. Most nation-state censors produce less than 4× amplification due to compact block pages.

2021-bock-weaponizing §5.5, Table 4 detection

Anycast CDN architecture dominates popular web content delivery: in the US, 59% of Alexa top-1k websites use anycast CDNs vs. 19% DNS-based; in Saudi Arabia, 57% use anycast CDNs. IP geolocation databases such as Maxmind are severely inaccurate for anycast infrastructure — reporting only <15% of Saudi Alexa websites as in-country vs. 90% measured by RTT-based multilateration — causing prior research to incorrectly attribute "nation-state hegemony" over developing-country Internet traffic.

2021-gosain-too §4.4, §6.3, Table 1 evaluation

CDN infrastructure causes 61%–92% of country-specific Alexa top-1k websites to be hosted within the client's own country across India, Iran, Saudi Arabia, Brazil, and the US, as measured by the authors' R-CBG multilateration technique achieving >89% accuracy. This traffic localization means web requests to popular sites rarely cross national borders, undermining the foundational assumption of decoy routing, domain fronting, CacheBrowser, and CovertCast.

2021-gosain-too §4.2, §5.2 evaluation

Filtering rules in Saudi Arabia were uniform across all three major ISPs (STC, Zain, Mobily) and six vantage points spanning four geographically distributed cities (Riyadh, Jeddah, Makkah, Al-Khobar), indicating a single centralized national filtering infrastructure rather than per-ISP implementation.

2020-alharbi-opening §3, §2.5 deployment

Saudi Arabia's blocking decisions closely track diplomatic ruptures: Qatari news sites were blocked in 2017 amid the Gulf crisis, Iranian news sites in 2018 following severed diplomatic relations, and Turkish outlets Anadolu and TRT Arabic in April 2020 amid Ankara–Riyadh tensions — the Turkish blocks were partly triggered by a citizen Twitter campaign calling for the block.

2020-alharbi-opening §3.3 policy

Internet filtering in Saudi Arabia is implemented primarily as HTTP URL-keyword filtering augmented by TLS-level (SNI) filtering for HTTPS connections; DNS and IP-level failures were minimal and consistent with transient network issues rather than deliberate blocking. In 2019, 82.2% of Adult, 7.6% of Shopping, and 6.2% of Games websites returned HTTP 403; TLS filtering of Shopping sites decreased from 9.6% to 6.6% between 2018 and 2020.

2020-alharbi-opening §3.1 detection

Saudi Arabia progressively unblocked VoIP and messaging applications after 2017: all 18 tested apps were blocked during 2013–2017, 67% were accessible in 2018, 93% in 2019, and all except WeChat in 2020, following CITC's 2017 announcement lifting the ban on compliant applications.

2020-alharbi-opening §3.2 evaluation

Between January 2017 and September 2018, ICLab conducted 53,906,532 measurements of 45,565 URLs across 62 countries and 234 ASes, detecting blocking of 3,602 unique URLs in 60 countries via DNS manipulation, TCP packet injection, and block page delivery. Iran blocked 20–30% of Alexa top-500 URLs — more than any other monitored country — while Saudi Arabia consistently blocked roughly 10%. The global trend in detected censorship shows a steady decrease, which the authors attribute to rising adoption of TLS and circumvention tools.

2020-niaki-iclab §V evaluation

Anonymization and circumvention tools (VPNs, Tor, etc.) are among the three most commonly blocked content categories across all commercial filters surveyed, alongside pornography and gambling. This holds across diverse products including Fortinet, Cisco, and government-deployed firewalls in Iran, Saudi Arabia, and Bahrain.

2020-raman-measuring §V-A-1, Fig. 7 evaluation

FilterMap identified 90 blockpage clusters from 90 vendors and actors across 103 countries using 374 million measurements from ~45,000 vantage points against 18,736 sensitive domains; 87 of these signatures were previously unknown. Commercial filters were detected in 36 out of 48 countries rated 'Not Free' or 'Partly Free' by Freedom House, with Fortinet alone present in at least 60 countries.

2020-raman-measuring §V deployment

The Great Firewall of China does not inject blockpages — it resets connections via TCP RST injection — making it invisible to blockpage-based detection systems. In contrast, the Iran firewall accounted for 97.1% of disruptions observed in Iranian vantage points, and the Bahrain and Saudi Arabia firewalls caused 71.2% and 80.2% of disruptions respectively, all using application-layer blockpage injection.

2020-raman-measuring §V-A-2 detection

The 30 key ASes computed from globally popular sites also intercept over 90% of paths to country-specific popular sites in nine censorious nations (China, Venezuela, Russia, Syria, Bahrain, Pakistan, Saudi Arabia, Egypt, Iran), covering 93.3% of paths to the top-50 country-specific sites. The same key AS set remained stable across repeated experiments conducted four months apart, suggesting durability over time.

2017-gosain-devil-s §6.1–6.2, Figure 8 evaluation

Never-once avoidance succeeds for 75% of source-destination pairs that do not already terminate in the US (a highly routing-central country) at δ=0.5, and for nearly all pairs avoiding less central countries. Russia is the hardest case at ~35% success (δ=0.5) due to proximity to the dense European node cluster. The median successful source-destination pair has over 1,000 valid DeTor circuits when avoiding the US and 500 when avoiding China.

2017-li-detor §6.2.1, §6.2.4 evaluation

Internet connectivity is the primary determinant of RAD attack strength across nation-state censors: China (573 ASes, 858 ring ASes) achieves a censorship metric of 0.277 under profile T1, while Syria (4 ASes, 5 ring ASes) achieves only 0.101 with the same decoy budget. Venezuela, despite fewer total ASes than Saudi Arabia (44 vs. 107), achieves a higher censorship metric (0.210 vs. 0.197) owing to its disproportionately large ring AS count (835 vs. 176), confirming that ring AS count predicts RAD capability better than raw AS count.

2016-nasr-game §6.4 / Table 6 evaluation

Across MENA countries (UAE, Tunisia, Oman, Iran, Qatar, Yemen, Saudi Arabia, Burma), over 80% of blockpage-delivering tests delivered the blockpage without DNS redirection, indicating transparent web proxies performing deep HTTP inspection rather than the cheaper DNS-intercept approach dominant in China. McAfee SmartFilter was identified in Qatar, Saudi Arabia, and UAE; Netsweepr in Qatar, UAE, and Yemen.

2015-gill-characterizing §5.1, Table VI evaluation

The Encore system collected censorship measurements from 88,260 distinct IP addresses across 170 countries over seven months via installations by at least 17 volunteer website operators. China, India, the United Kingdom, and Brazil each contributed at least 1,000 measurements; Egypt, South Korea, Iran, Pakistan, Turkey, and Saudi Arabia each contributed more than 100.

2015-narayanan-no Introduction evaluation

Five commercial filtering products (FortiGuard, Squid, Netsweeper, Websense, WireFilter) were identified in 7 of 36 block-page clusters via copyright notices in HTML comments, HTTP header strings, or URL path patterns; the remaining 29 clusters contained no identifying markup. WireFilter was first detected in the wild in Saudi Arabia (AS 25019) in 2011, representing a newly deployed filtering product not previously observed in measurements.

2014-jones-automated §5.2, Table 2 detection

Applying automated block-page detection to the ONI dataset (49 countries, 2007–2012) reveals that Burma's (AS 18399) censorship mechanism shifted from DNS redirection to a transparent proxy returning a custom block page in mid-2009, then block pages largely disappeared after Burma's late-2011 political liberalization. Saudi Arabia (AS 25019) shows a similar transition with WireFilter replacing an unidentified prior tool in 2011, with two concurrent block-page templates suggesting multiple simultaneous filtering devices.

2014-jones-automated §6 evaluation

All confirmed URL filtering deployments—McAfee SmartFilter in UAE and Netsweeper in Yemen, UAE, and Qatar—block content across at minimum six of seven tested human-rights-sensitive categories: media freedom, human rights, political reform, LGBT, religious criticism, and minority groups/religions. Netsweeper in both Qatar (Ooredoo) and UAE (Du) blocks all seven categories. This content is protected under Article 19 of the Universal Declaration of Human Rights.

2013-dalek-method §5, Table 4 policy

The paper presents a repeatable method for confirming which specific URL filtering product is used for censorship: create test domains under researcher control, submit a subset to the vendor's public URL categorization interface, then retest within 3–5 days to observe whether submitted domains become blocked. This technique confirmed McAfee SmartFilter in UAE (Etisalat, AS 5384) and Saudi Arabia (Bayanat Al-Oula AS 48237, Nournet AS 29684), and Netsweeper in Qatar (Ooredoo AS 42298), UAE (Du AS 15802), and Yemen (YemenNet AS 12486).

2013-dalek-method §4.2, Table 3 evaluation

Across 11 countries, censorship execution falls into at least six distinct categories: DNS redirect to localhost (Malaysia, Russia, Turkey), DNS redirect with warning page (South Korea), connection timeout with no notification (Bangladesh, India), spoofed TCP RST injection (China), spoofed HTTP 403 with warning page (Bahrain, Iran), HTTP 302 redirect (South Korea, Thailand), and spoofed HTTP 200 iframe response (Saudi Arabia). Four countries censor at DNS and eight at routers, with South Korea employing both layers simultaneously.

2012-verkamp-inferring Table 3 evaluation

Thailand uses an out-of-band device to inject spoofed HTTP 302 redirect responses, so the destination server still receives and responds to the original request — unlike inline censors in Bangladesh and India where the request is dropped before reaching the server. Saudi Arabia similarly uses an out-of-band device to inject a spoofed HTTP 200 response containing an iframe warning page loaded from a separate IP address, allowing the warning page content to be updated without modifying the censoring module.

2012-verkamp-inferring §4.2, §5 detection