Facebook has started testing end-to-end encryption on secret conversations, using the Signal Protocol developed by Open Whisper Systems. The company noted Messenger already uses strong security systems but will put additional safeguards on conversation users want to keep private, be it for sending financial information to an accountant, for example, or when discussing private information like an illness or a health issue.
The encrypted messages will only be read on the one device of the person the user is communicating with. Users within a secret conversation can also choose to set a timer to control the length of time each message sent remains visible within the conversation.
The technology uses the Signal Protocol developed by Open Whisper Systems. Starting secret conversations with someone will be optional and not able to support rich content like GIFs and videos, making payments, or other Messenger features, yet. Secret conversations are available on a limited test basis right now, but will become more widely available this summer.
