The use of the messaging platform by Waltz raises new security issues

Michael Waltz was heard with the White House when, as a national security advisor, he inadvertently added a journalist to a sensitive signal cat, a commercial messaging application.

Now, when he leaves this work, he raised a new set of questions on the use of the White House of the encrypted application. A photograph of him looking at his phone on Wednesday at a meeting of the cabinet clearly shows that he communicates with his colleagues – including the Secretary of State and the Director of National Intelligence – using a platform originally designed by an Israeli company which collects and stores signaling messages.

This discovery of the new system came when a Reuters photographer, standing just above Mr. Waltz’s left shoulder, took a photo of his phone.

He did not use a confidentiality screen, and during the zoom, the photo shows a list of messages and calls from several senior officials, including vice-president JD Vance and Steve Witkoff, the special envoy that negotiates on three fronts: Israel-Hamas discussions, dance increasingly held with Vladimir V. Putin on Ukraine and Iran nuclear discussions. Secretary of State Marco Rubio and Tulsi Gabbard, the national intelligence director, are also on his discussion list.

Although the application that Mr. Waltz was seen used on Wednesday looks like signal, it is in fact a different platform from a company that announced it as a way to archive messages for file holding. This is essential, because a concern that arose when senior officials used the application was whether it respects the federal rules of file holding.

One of the signal advantages is that it is both encrypted and can be defined to automatically delete messages. But although this is a feature for users looking for secure communications, this is a problem for national archives, because it seeks to keep files.