(Can’t) Picture This 2
An Analysis of WeChat’s Realtime Image Filtering in Chats

In this work, we study how Tencent implements image filtering on WeChat. We found that Tencent implements realtime, automatic censorship of chat images on WeChat based on what text is in an image and based on an image’s visual similarity to those on a blacklist. Tencent facilitates this realtime filtering by maintaining a hash index of MD5 hashes of sensitive image files.

Featured Publications

The Predator in Your Pocket: A Multidisciplinary Assessment of the Stalkerware Application Industry

This report was collaboratively written by researchers from computer science, political science, criminology, law, and journalism studies. As befits their expertise, the report is divided into several parts, with each focusing on specific aspects of the consumer spyware ecosystem, which includes: technical elements associated stalkerware applications, stalkerware companies’ marketing activities and public policies, and these companies’ compliance with Canadian federal commercial privacy legislation.

Burned After Reading: Endless Mayfly’s Ephemeral Disinformation Campaign

Endless Mayfly is an Iran-aligned network of inauthentic websites and online personas used to spread false and divisive information primarily targeting Saudi Arabia, the United States, and Israel. Using this network as an illustration, this report highlights the challenges of investigating and addressing disinformation from research and policy perspectives.

Lifting the lid off the Internet.

The Citizen Lab is an interdisciplinary laboratory based at the Munk School of Global Affairs & Public Policy, University of Toronto, focusing on research and development at the intersection of information and communication technologies, human rights, and global security. Learn more.

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Privacy Policy

Features & News

Canada’s New and Irresponsible Encryption Policy: How the Government of Canada’s New Policy Threatens Charter Rights, Cybersecurity, Economic Growth, and Foreign Policy

The proposed rationales for weakening encryption would exchange marginal gains in limited investigative situations for significant loses with regards to Canadians’ abilities to exercise their rights and freedoms while simultaneously undermining cybersecurity, economic development, and foreign affairs. Minister Goodale should stop calling persons with well-considered policy positions on the importance of enabling the availability of strong encryption as supporters of child abusers, and get on with his job of trying to keep Canadians safe instead of endangering them with his irresponsible and dangerous encryption policy.

Citizen Lab at FOCI ’19

This year, Citizen Lab researchers will present on issues ranging from WeChat image filtering to the methodologies used for identifying commercial spyware abuses.

“未阅先焚” 2: 微信如何实现实时审查用户对话中的敏感图片

本报告延续上一篇针对微信朋友圈图片过滤技术的研究,分析微信如何在聊天功能中实现实时图片过滤。微信是中国腾讯控股有限公司旗下的即时通讯应用,目前是中国最受欢迎的聊天软件之一,也是全球排名第四的最流行聊天软件。朋友圈是微信上最常用的功能之一,其中图片是用户最期望看到的内容分享形式。

The Dangerous Effects of Unregulated Commercial Spyware

In recent days, United Nations Special Rapporteurs have released two revelatory reports that demonstrate the dangerous effects of unchecked technology in the hands of autocrats: one relating to the proliferation and abuse of surveillance software and one that investigates the murder of Washington Post journalist Jamal Khashoggi. Both reports highlight the danger of unaccountable and unregulated surveillance technology sold to countries with egregious human rights records.

Featured Video

The NSO connection to Jamal Khashoggi

Citizen Lab senior research fellow Bill Marczak and Saudi dissident Omar Abdulaziz joined CNN to discuss how NSO’s Pegasus spyware found on Omar’s phone is linked to Jamal Khashoggi.

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Munk School of Global Affairs & Public Policy | University of Toronto