5.1 The identity concept

Let’s recall from Chapter 2, Secure Channel and the CIA Triad that entity authentication is the ability to assure one communicating party – using fresh supporting evidence – of the identity of a second communicating party and to ensure that the second party was actually active when the supporting evidence was generated [117].

But what do we actually mean by the term identity? According to the Merriam-Webster online dictionary, identity is the distinguishing character or personality of an individual as well as the condition of being the same with something described or asserted. In cryptography, identity typically refers to a unique property of a communicating party. This actually can mean a lot of things; it might be the name that can be found in your passport, or the pseudonym you have chosen for yourself when posting on www.dogforums.com. As communicating parties very often involve computers, it might also be the name of a server...