"Calls Chat" is essentially Signal with a different coat of paint.
In recent months, Telegram has come under increasing pressure to take care of the neo-Nazi terrorism problem that is festering on the platform.
Phantom Secure made custom, encrypted BlackBerry phones and sold them to customers all over the world, including to the Sinaloa cartel, according to prosecutors.
The encryption debate has reached the Kremlin.
A new program dubbed Muslim Crypt tries to keep extremist communications secure.