ABSTRACT
When communicating via the Internet, how do we know that someone is who they say they are? In addition, how can we be assured that the information we have obtained is not only valid, but has originated from the source where we requested it? We gain the assurance that we are indeed communicating with the proper individuals and have obtained the proper data through what is called authentication. In other words, it is Bob that is communicating with Alice and not the devil, as illustrated in Figure 20.1.
