*Created by: markborkum* ### Pacifica Notifications version n/a ### Pacifica Core Software versions n/a ### Platform Details n/a ### Scenario: The receiver should be able to authenticate and validate the event source for CloudEvents notification messages. For example, when the receiver registers a new subscription, the receiver may supply a nonce (e.g., a bearer token) that must be incorporated into the URI for the `/receive` endpoint or included as an HTTP header. Alternatively, the sender and receiver could use cryptography (i.e., payload signing). ### Steps to Reproduce: n/a ### Expected Result: n/a ### Actual Result: n/a