Overview of the Sample Protocol

This protocol provides a standard way for two parties to create an authenticated, real-time connection between themselves. The end result of this protocol is a session key that is shared by both of the parties involved. This protocol is known as a three-phase protocol because it requires that the two parties exchange three packets of data in the process of creating the shared session keys. This is shown in the following illustration, reading from top to bottom.

A variety of key exchange protocols can be implemented using CryptoAPI. The protocol discussed here is just one of many possibilities. However, using this particular protocol will tend to increase your application's potential interoperability.

Following is a description of this protocol. One of the parties is arbitrarily designated the sending user (or sender) and the other the destination user (or receiver).