Authentication - Authorization

Authorization

The process of authorization is distinct from that of authentication. Whereas authentication is the process of verifying that "you are who you say you are", authorization is the process of verifying that "you are permitted to do what you are trying to do". Authorization thus presupposes authentication.

For example, a client showing proper identification credentials to a bank teller is asking to be authenticated to act on behalf of the account holder. A client whose authentication request is approved becomes authorized to access the accounts of that account holder, but no others.

Even though authorization cannot occur without authentication, the former term is sometimes used to mean the combination of both.

To distinguish "authentication" from the closely related "authorization", the short-hand notations A1 (authentication), A2 (authorization) as well as AuthN / AuthZ (AuthR) or Au / Az are used in some communities.

Normally delegation was considered to be a part of authorization domain. Recently authentication is also used for various type of delegation tasks. Delegation in IT network is also a new but evolving field.