The final entity that needs to be introduced is the Individual. An Individual is a human being that is using the client. In any given situation, an Individual may or may not exist. Clients can act as front ends for Individuals, or clients may be independent entities that are set up and allowed to run autonomously. An example of such an independent entity can be found in the Trust Router Protocol (https://www.ietf.org/proceedings/86/slides/slides-86-rtgarea-0.pdf), where the routers use ABFAB to authenticate to each other.