Signal’s convenience and the lack of clear agency guidelines makes the commercial app a popular choice for government officials. But transmitting sensitive information is still prohibited.

The Signal messages reveal a contempt for European allies among Trump’s most senior people, which will be difficult to repair ...

Downloads of the app surged in the past week after the Atlantic published White House officials’ texts about a military ...

From war plans to surveillance secrets, America's biggest intelligence leaks have exposed military strategies, covert ...

A routine discussion among top US officials on a messaging app which also had the editor-in-chief of a leading American ...