Mike Waltz, who was until Thursday U.S. National Security Advisor, has inadvertently revealed he is using an obscure and unofficial version of Signal that is designed to archive messages, raising questions about what classification of information officials are discussing on the app and how that data is being secured, 404 Media has found.
On Thursday Reuters published a photograph of Waltz checking his mobile phone during a cabinet meeting held by Donald Trump. The screen appears to show messages from various top level government officials, including JD Vance, Tulsi Gabbard, and Marco Rubio.
At the bottom of Waltz’s phone’s screen is a message that looks like Signal’s regular PIN verification message. This sometimes appears to encourage users to remember their PIN, which can stop people from taking over their account.