Yesterday, Facebook owned WhatsApp turned on full end-to-end encryption for its communications.
The company announced that they had completed an integration that has lasted for nearly a year and a half.
WhatsApp began rolling out encrypting text messages in November 2014, as part of a partnership with Open Whisper Systems, but the protection now extend to voice calls, video, and multi-party chat rooms, for users on both iOS and Android.
Once communications with a user are encrypted, the WhatsApp client will now notify the user and refuse to send any unencrypted messages, addressing previous concerns that the system might be vulnerable to a downgrade attack.
Open Whisper’s protocol is open source, and the group has pledged to help other messenger services employ the same protections going forward.
However, it is important to note that WhatsApp’s system still manages messages centrally, coordinates key exchanges, and has significant control over the code that runs on both servers and phones.