What is the Signal messaging app and how secure is it?

 

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The free messaging app Signal has made headlines after the White House confirmed it was used for a secret group chat between senior US officials.

The editor-in-chief of the Atlantic, Jeffrey Goldberg, was inadvertently added to the group where plans for a strike against the Houthi group in Yemen were discussed.

It has caused a significant backlash, with Democrat Senate leader Chuck Schumer calling it "one of the most stunning" military intelligence leaks in history and calling for an investigation.

But what actually is Signal - and h

Signal has estimated 40-70 million monthly users - making it pretty tiny compared to the biggest messaging services, WhatsApp and Messenger, which count their customers in the billions.

Where it does lead the way though is in security.

At the core of that is end-to-end encryption (E2EE).

Simply put, it means only the sender and the receiver can read messages - even Signal itself cannot access them