As it had promised back in August, Facebook Messenger has now fully enabled optional end-to-end encrypted group chats, voice calls and video calls for mobile apps.
"We know that people expect their messaging apps to be secure, private and provide them a space to be expressive," Messenger product manager Timothy Buck wrote in a blog post last week. "This is why we are continuing to introduce some of the rich features that you already love in Messenger to end-to-end encrypted chats."
End-to-end encryption (E2EE) on group chats and calls is a further extension of the Secret Conversations option that has been part of Facebook Messenger since 2016. At that time, it was available only to one-on-one chats, but in August 2021, E2EE became available for one-to-one voice and video calls too.
How to turn on Messenger end-to-end-encrypted chats
Keep in mind that in all cases, Messenger does not use end-to-end encryption by default. You have to select the E2EE option at the beginning of a chat or call, and you can't retroactively make an existing chat end-to-end encrypted.
The end-to-end-encryption option is not available for Messenger client apps on Windows, Mac or Facebook Portal. However, all WhatsApp chats and calls are end-to-end encrypted by default.
But in general, you need to first tap the pencil icon in the top right of the screen, then toggle on the little lock icon, create a new group and add participants. Once the E2EE-enabled group has been created, you can start an E2EE chat, voice call or video call with the group.
Other new Messenger features
Messenger also announced the debut of several other features, including:
- Screenshot notifications tell you when someone else on a call has taken a screenshot of a disappearing message that you sent.
- Typing indicators tell when someone else on a one-to-one or group E2EE chat is typing.
- GIFs and stickers are now available for E2EE chats.
- Reaction emojis are also available for E2EE chats.
- You can reply to specific messages in E2EE chats by long-pressing or swiping on the messages. You can also forward messages by long-pressing on them.
How end-to-end encryption works
End-to-end encryption is a step up from regular communications encryption because even the communications provider — in this case, Facebook aka Meta — is not able to see the contents of the message or call.
Normally, encryption extends only from your phone or computer to the communications provider's server. At the server, the message or call is decrypted, then re-encrypted and passed along to other people who may be on the call or chat.
That creates a privacy weakness that can be exploited by malicious staffers, spying software or police investigators (or, as the Messenger blog post diplomatically put it, "hackers, criminals and other prying eyes").
End-to-end encryption removes this weakness and makes sure that only the people who are on the call or chat can see the contents of the communications. Many of the best encrypted messaging apps, including Signal, Threema and the aforementioned WhatsApp, make E2EE the default.
Law enforcement officials in many countries say their digital-surveillance operations are "going dark" as a result, but security and privacy experts, including some former government officials, say E2EE is necessary in an increasingly digital world.