Facebook Messenger’s Secret Conversations feature, which allows end-to-end encryption of messages exchanged by two users that have enabled the option, has finally been rolled out to all Messenger users.
Announced in July, Secret Conversations is based on the Open Whisper Systems’ Signal Protocol.
The thing to keep in mind is that the feature is not turned on by default, so you have to actively choose to secure your messages.
Another option that the feature gives users is the ability to make messages disappear after a period of time determined by the sender, but users should be aware that in that period of time, the recipient can make screenshots of the conversation and thus be able to share it with others.
Secret conversations are identified by a padlock icon by the collocutor’s profile picture.
For the time being, only text messages, pictures and stickers can be sent via secret conversations. Group messages, gifs, videos, voice or video calling, or payments are still not supported.
To use it, you have to turn on the feature (find it in the “Me” tab in the Messenger app), and then, when creating a new message, remember to go for the offered “Secret” option.
Both people in a secret conversation can verify that the messages are end-to-end encrypted, by checking whether the other user’s device key is the same one they see on their device.
You can check the keys by tapping on the collocutor’s name at the top of the conversation screen.
But, Facebook reassures that even if you don’t, you can be sure that the conversation is encrypted.