Signal is one of the best end-to-end encrypted messaging services, available for both Android and iPhone. Earlier this year, support for video and audio calls began to roll out. Now the team is working on something a bit more basic - profile pictures and names.
Signal explained in a blog post that it wanted to implement user profiles (containing a name and picture) without compromising any level of security, and the current solution is pretty smart. When you fill out your profile, it is encrypted with a unique key. The encrypted material is uploaded to Signal's servers, but Signal itself cannot view the data (because it's encrypted).
The app follows a set of guidelines to determine who is given access to your profile (and thus, sent a copy of the key). Any contacts you have saved on your phone and conversations you create will see your name/picture. In addition, you can choose to explicitly grant anyone outside those groups access to your profile.
Signal Profiles are currently only available in the beta program, which you can join by clicking here. Once you join the beta, just download the latest Signal update (or download it from the Play Store below, if you don't already have it).