How claiming establishes ownership
The claim URL carries the plaintext device claim token to a dedicated flow. After Google authentication, the server associates that token record with the account and updates previously uploaded chats carrying its hash. The public chat URLs and their content do not change.
Later requests from the same device continue sending the claim token. The server resolves the linked owner and stores that owner on new chat documents, so they appear in My shares without another claim action.
Account data is intentionally limited
Google provides the email address, display name, and profile-image URL used by the account session. InstaShare uses a database-backed session and does not ask for a separate InstaShare password.
Signing in is an ownership and management feature. It does not make public shares visible only to the signed-in user, and signing out does not disable links.
Device management remains separate from content management
The account page shows claimed devices, their hostname when supplied, when they were first and last used, and the number of shares made. Revoking a device prevents its current claim token from attaching more uploads. Existing owned shares remain until individually deleted.