People can toggle the Secret Conversations feature on in settings to enable end-to-end encryption on Facebook Messenger.
To recall, the feature was began rolling out in August, and the company has confirmed to Wired that is now available for all of its 900 million users. The feature was first announced in July, which is also when the first tests were launched.
Unfortunately, unlike with WhatsApp, where all messages are automatically encrypted, the nearly one billion monthly active Messenger users will have to activate end-to-end encryption for every new message. In the case of WhatsApp, users had only needed to have the latest version to ensure that all their chats were end-to-end encrypted. Users that download or update to the latest version of Facebook Messenger will now see the ‘Secret’ option in the top right corner of the New Message screen. For the end-to-end encryption to work, which ensures no-one including Facebook can read your messages, both the sender and receiver need to be on the latest edition of the app. The update is available for both Android and iOS, however, the changelog on Google Play and the App Store does not detail the new feature.
Once they enable the option in a new message, the app will show users the following notification, “Your messages are already secure, but Secret Conversations are encrypted from one device to another.” The end-to-end encryption is powered by the same encryption system used on the Edward Snowden-approved Signal app, developed by Open Whisper Systems.