Technology preview: Sealed sender for Signal

In addition to the end-to-end encryption that protects every Signal message, the Signal service is designed to minimize the data that is retained
about Signal users
. By design, it does not store a record of your contacts, social graph, conversation list,
location, user avatar, user profile name, group memberships, group titles, or group avatars.

We have been exploring techniques to further reduce the amount of information that is accessible to the service,
and the latest beta release includes changes designed to move Signal incrementally closer to the goal of hiding another piece of metadata:
who is messaging whom.