Authentication

Stores use DIDs to authenticate and verify data. Connecting to a store proves who you are through a challenge: the store sends a random nonce, and you return it signed by a key in your DID document. The signature covers the specific store and expires shortly, so a captured response cannot be replayed.

Authentication governs what you may ask a store to do — host, pin, spend quota. It does not protect your data; that is a property of the documents themselves.