The encryption is peer to peer, which means that Silent Circle doesn’t centrally hold a key that can be used to decrypt people’s messages or phone calls. Each phone generates a unique key every time a call is made, then deletes it straight after the call finishes. When sending text messages or images, there is even a “burn” function, which allows you to set a time limit on anything you send to another Silent Circle user—a bit like how “this tape will self destruct” goes down in Mission: Impossible, but without the smoke or fire. [Oct. 16, 2012]In a Feb. 4, 2013 article Gallagher says
Until now, sending encrypted documents has been frustratingly difficult for anyone who isn’t a sophisticated technology user, requiring knowledge of how to use and install various kinds of specialist software. What Silent Circle has done is to remove these hurdles, essentially democratizing encryption. It’s a game-changer that will almost certainly make life easier and safer for journalists, dissidents, diplomats, and companies trying to evade state surveillance or corporate espionage.