Facebook has added a lot of features to its Messenger app, while they are trying to remove messages from Facebook. They have recently told about Messenger secret conversation. Facebooks end-to-end encrypted chat will have the label of secret conversation.
The social media giant is currently offering this new privacy feature to only a small portion of its 900 billion users. End-to-end encryption is already available on other messaging which makes it necessary to introduce it in Messenger. Facebook owned WhatsApp has full-time end-to-end encryption. But, the end-to-end encryption getting tested on the Messenger app is optional. This means that you have to manually turn on the secret conversation, which is not turned on by default. Also, Googles Allo features the optional end-to-end encryption.
This will allow you to send messages which can not be seen by anyone else except the sender and receiver. You can also set a self-destruct timer for the messages you send. There is option to set timer ranging from 5 seconds to 6 hours. If you set 1 minute timer, then the message will disappear 1 minute after the person read the message. The encrypted messages will be accessible to read only one primary device which means if you switch devices in between chat, you will not be able to read earlier seen encrypted messages.
The technology used by Facebook is the same as used in WhatsApp and Googles Allo, which is Signal Protocol developed by Open Whisper Systems. Because developing own encryption algorithm will be a tough task for companies, they prefer to use open source Signal Protocol.
If you are part of test, then you will find that secret conversation limits other Messenger features. That is why it is kept optional. Also, note that secret conversations will not allow sharing of rich content like gifs and videos. It also restricts making payments through Messenger.
If you are part of testing, then let us know in comments. Otherwise wait for the feature to roll out for public.