The 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.
Signal’s creator Matthew Rosenfeld – who is better known by the pseudonym Moxie Marlinspike – joked the “great reasons” to join the platform now included “the opportunity for the vice president of the United States of America to randomly add you to a group chat for coordination of sensitive military operations”.
But others are not seeing the funny side, 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 how secure or otherwise were the senior politicians’ communications on it?
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.
