Abstract: Techniques are provided to create and manage groups of users. A group can be treated as a single entity. For privacy of a user, user keys can be translated to group keys, which are then used to access resources. The user can prove membership in the group via their keys (e.g., using a diversified public key), and then get the group keys in response, e.g., after verification to a group server using a diversified user key.

Abstract: The subject technology provides systems and methods for context-based user status indicator selection. In an example, a method includes obtaining, by a first electronic device associated with a first user, status indicators, each of which indicates a respective status of a second user of a second electronic device. Furthermore, the method includes determining, by the first electronic device, a respective relevance priority of each of the status indicators. Based on the determined respective priorities, a subset of the status indicators is selected by the first electronic device and is displayed in a graphical element on the first electronic device.

Abstract: A plurality of optical transmission sources provide data communication from a transmitting module to a common detector cooperative with a receiving module, the modules being subject to relative rotation about a shared axis. The detector can be located on the shared axis, each of the sources directing a beam onto the detector regardless of relative module orientation, and/or the light can be diffused, so that it is detected regardless of source and detector placement and relative module orientations. Transmissions can be distinguished according to synchronized timing, differing optical frequencies, differing baud rates, and/or differing circular polarizations. The detector can split the light into a plurality of beams which pass through different optical filters and are thereby distinguished. Cut-off circuits can prevent failed sources from transmitting. A diffused second light source and a second plurality of detectors can provide reverse communication from the receiving module to the transmitting module.

Abstract: A plurality of optical transmission sources data provides data communication from a transmitting module to a common detector cooperative with a receiving module, the modules being subject to relative rotation about a shared axis. The detector can be located on the shared axis, each of the sources directing a beam onto the detector regardless of relative module orientation, and/or the light can be diffused, so that it is detected regardless of source and detector placement and relative module orientations. Transmissions can be distinguished according to synchronized timing, differing optical frequencies, differing baud rates, and/or differing circular polarizations. The detector can split the light into a plurality of beams which pass through different optical filters and are thereby distinguished. Cut-off circuits can prevent failed sources from transmitting.