Nearby sharing security
Nearby sharing is a visionOS feature that allows people to share content from their apps with other nearby visionOS users. Nearby sharing is set to Contacts Only by default, which means both parties need to be in each other’s Contacts to allow automatic discovery. Non-contacts can pair using a manually-exchanged PIN displayed on the initiator’s device and entered on the joiner’s. Users can choose to turn off the feature entirely by deselecting “Allow Nearby People” in Settings or Control Center.
When a user chooses to share content, a secure SharePlay session is established and used for sharing the content between the participants. Content actively being shared in a Nearby Sharing session is highlighted to the user with a green visual indicator.
To allow virtual objects to be placed in the same location for all users, Collaborative Map Building (CMB) takes place when devices first connect. They exchange information about reference objects within their environment to establish a shared coordinate system for virtual object placement. As CMB can be used to infer location, it’s initially performed only after a user accepts an invitation to join a Nearby Sharing session with a given participant. However, for up to 45 days after that initial invite is accepted, CMB runs opportunistically for subsequent invites that occur in that same location with that participant. CMB data is also transmitted using end-to-end encryption, and map merging happens locally on each device; no centralized spatial map is ever stored or shared beyond the participants.