The Web Services Secure Conversation technology has message optimization benefits. While providing better message-level security it also improves the efficiency of multiple-message exchanges. It accomplishes this by providing basic mechanisms on top of which secure messaging semantics can be defined for multiple-message exchanges. This feature allows for contexts to be established so that potentially more efficient keys or new key material can be exchanged. The result is that the overall performance of subsequent message exchanges is improved.
For more information on how to use Secure Conversation, see Chapter 7, Using WSIT Security.