Abstract: Secure site-to-site transactional communication between at least two network servers coupled to a data communication network, including secure registration by an authentication server associated with a multi-site user authentication system. A network server receives a request via a browser f of a client computer. In response, the network server initiates a transaction with the authentication server and defines a data structure, such as a query string, associated with the transaction. The network server also generates a digital signature of the data structure and then adds it to the data structure before directing the client computer from the network server to the authentication server with the data structure and the added digital signature. The network server also adds an index to the data structure. The index is associated with the transaction and unique, per transaction, to the network server initiating the transaction.

Abstract: Enabling dynamic aggregation of content from a plurality of content providers. The invention stores references associated with specific display areas in a document for a particular data source. Responsive to a request for the document, the invention retrieves the references associated with the data source and dynamically inserts the references into the appropriate display area of the document. A client renders the document by obtaining the content associated with the references. In an embodiment, the invention includes a web service for cobranding a login user interface for a user authentication system. The web service places cobranding content provided by an affiliate content provider and sign-in user interface content provided by a user authentication service into different frames of a single web page.