Content analysis of 7,000 randomly sampled keywords (±1.1% at 95% confidence) found Social content (gambling, illicit goods, competitor references) was the dominant theme at 51.16%, followed by Technology/URLs at 16.81%, Political content at 15.00%, People (officials, dissidents) at 6.57%, and Event-related keywords at only 4.89%. Gaming keyword lists lacked references to current events from 2016–2017 that were found actively censored on Chinese chat applications during the same period, suggesting games face lower scrutiny for real-time event censorship than communication platforms.

Chinese mobile games widely implement keyword censorship client-side — blacklists were found embedded in plain text, XML, JSON, compiled Lua, compiled C++, and encrypted formats requiring reverse engineering to extract. The client-side implementation exposed 132 keyword lists from 113 different games in the first experiment alone. Games must submit their blocked keyword list to regulators (MOC/SAPPRFT) to obtain a publication license, making keyword filtering a regulatory compliance artifact rather than purely an operational choice.

§2, §3.1 detection

Analysis of over 183,111 unique keywords collected from 200+ Chinese mobile games found no central state or provincial authority controlling keyword list generation. The only consistently significant predictors of keyword list similarity were whether games shared the same developer (Mantel r=0.17, p<0.001) or publisher (r=0.15, p<0.001); city, province, and genre showed no significant correlation (p>0.58). This indicates Chinese companies have substantial flexibility in determining which content to block under the 'self-discipline' intermediary liability framework.

§4.1–4.2 policy

When controlling for shared-developer as a confound, shared-publisher correlation collapsed to r=0.047 (p=0.0015) in the first experiment and r=0.064 (p=0.015) in the second; when controlling for shared-publisher, shared-developer remained r=0.095 (p<0.001) and r=0.13 (p<0.001) respectively. This demonstrates that development teams — not publishing entities — are the primary locus of keyword list authorship in the Chinese mobile gaming ecosystem.

§4.1–4.2 evaluation

Forensic analysis of keyword list formatting artifacts — C-style escapes appearing in XML files, XML entities appearing in non-XML files, and double-backslash encoding traceable to a 2004 leaked QQ keyword list — provides evidence that developers copy and circulate keyword lists across companies through informal channels including old web applications and bulletin boards. This keyword propagation mechanism explains partial overlap between unrelated companies' lists without implying a central authority.

§5.1 detection

During the June 2025 shutdown, Iranian authorities blocked international One-Time Password (OTP) SMS delivery, preventing new sign-ins to foreign secure-messaging platforms and VPN services. This forced users toward government-approved domestic platforms that lack security and privacy protections. The blockade of OTPs effectively weaponized account-recovery flows as a secondary shutdown layer, disproportionately affecting users who needed to activate new circumvention tools during the crisis.

2025-iran-shutdown-measurement §Human Rights Implications port-blockingdpikeyword-filtering

Simple character-level perturbations (English) and homophone substitutions (Chinese), combined with LLM instruction-following prompts directing the model to use word substitutions in its output, successfully bypassed all input and output filters for all 41 input-blocked and 197 output-blocked queries across five major Chinese LLM services (Baidu-Chat, DeepSeek, Doubao, Kimi, Qwen). Every input-blocked query contained at least one keyword combination that alone triggered the filter, confirming keyword-matching rather than semantic classification.

2026-ablove-characterizing §VII-D keyword-filtering

Cross-national experiments conducted from Singapore, South Korea, and Taiwan during February 19–24, 2025 found no variance in blocking implementations, event syntax, or server infrastructure across all five Chinese LLM services. Input blocking was enacted identically in all three international locations, and services connected to the exact same server IP addresses globally — Kimi and Baidu-Chat connected to identical IPs and DeepSeek to the same two addresses across all tested locations.

2026-ablove-characterizing §VIII-A keyword-filtering

Input blocking in Chinese LLM services (DeepSeek, Qwen, Kimi, Doubao) is overwhelmingly consistent: all four services persistently block the exact same queries across all 5 measurement samples in both Simplified and Traditional Chinese. Output blocking is far less consistent, with only 29 out of 349 output-blocked queries blocked across all 5 samples. Baidu-Chat is exceptional: it performs almost no input blocking but instead relies heavily on post-search and output blocking (78.6% of blocks are output-phase).

2026-ablove-characterizing §VI-B keyword-filteringdpi

DeepSeek, Kimi, and Doubao all transmit analytics logs to the same Autonomous System (AS24429, Zhejiang Taobao Network Co., Ltd., a ByteDance/Volcengine subsidiary), with one monitoring endpoint IP directly overlapping between DeepSeek and Doubao. Additionally, all four non-Qwen services maintain connections with servers physically located in China throughout the chat session, transmitting user IDs, session IDs, viewport data, language preferences, and in Baidu-Chat's case, the full query text via URL-encoded CAPTCHA requests.

2026-ablove-characterizing §VI-D keyword-filtering

All five Chinese LLM services transmit partial or complete responses to the client machine even when output blocking is triggered, representing a major information leak. For DeepSeek and Qwen, truncated blocked responses are on average close in token length to full successful responses. For Baidu-Chat, the complete response is transmitted to the client but only partially rendered in the browser UI, with only a word or two visible on screen.

2026-ablove-characterizing §VI-C keyword-filtering