Beijing (AFP)

The Signal secure messaging app, one of the few foreign platforms so far not blocked in China, appeared to be inaccessible on Tuesday in a country where the internet is tightly controlled.

China has an extensive Internet surveillance system that allows it to purge any content deemed sensitive, such as political criticism or pornography.

And in the name of stability, the country requires the digital giants to have their own censors to carry out this task upstream.

Failing to comply with these regulations, the vast majority of foreign search engines and social networks (Google, Facebook, Twitter ...) are blocked in China and can only be used with bypass software - a VPN.

According to the Greatfire.org site which tracks online censorship in China, the Signal app has been inaccessible in the country since at least March 15.

However, it is available on the Chinese App Store, the application store of the American giant Apple.

Signal did not immediately respond to a request for information from AFP.

The app has so far been installed nearly 510,000 times in China on Apple phones or tablets, according to research firm Sensor Tower.

And globally, Signal has passed the milestone of 100 million cumulative downloads on the AppStore and Google Play, the competing platform.

Launched in 2014, Signal is considered by specialists as one of the most secure messaging applications on the market thanks in particular to its ability to encrypt "end-to-end" audio and video messages or calls.

The app gained notoriety in January when its competitor WhatsApp warned that it would share more data with its parent company Facebook, angering many users.

Faced with the controversy, WhastApp had announced to postpone by three months the entry into force of its new terms of use.

Iconic Tesla boss Elon Musk himself publicly touted Signal messaging at the time.

And the app had been the top downloads in several countries, including India, France and Germany.

Signal thus joins a long list of foreign services blocked in China.

Last month, Beijing banned Clubhouse, an American app that allows users to participate in live, invitation-only conversations.

© 2021 AFP