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Studies of Internet filtering, network interference, and other technologies and practices that impact freedom of expression online. 

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微信監控诠釋

公民實驗室2020年5月7日發布報告指出,中國最流行的社交媒體軟件微信是對平台上的文檔和圖像內容實施監控,並使用監控所得的數據訓練其審查系統。本文是對該報告的概述,以及與研究團隊的一些常見問答。

WeChat Surveillance Explained

On May 7 2020, the Citizen Lab published a report that documents how WeChat (the most popular social app in China) conducts surveillance of images and files shared on the platform and uses the monitored content to train censorship algorithms. This document provides a summary of the research findings and questions and answers from the research team.

“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。

(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.