The buyer and seller exchange authentication data provided by their security systems to authenticate the transaction. Back Office Transaction, Third Party Security Service. Buyer authenticates with security service. Security service provides authentication document to buyer. Seller authenticates with security service.
Security service provides authentication document to seller.
Buyer and seller execute transaction, providing authentication documents to each other. Authentication documents include authz attributes and authn event description. Added set of high-level use cases. Changed diagrams of detailed use case scenarios to use sequence diagrams instead of use case diagrams. Added description of each use-case scenario and list of requirements flowing from the scenario.