Ian Yip’s take on access management versus entitlement management can be partially summed up with this equation:
Entitlement management is simply fine-grained authorisation + XACML
I have four problems with this.
First, definitions that include a protocol are worrisome as they can overly restrict the definition. For example, if I defined federation as authentication via SAML, people would quickly point out that authentication via WS-Fed was just as viable as a definition. So in terms of an industry conversation, we need to make sure that our terms are not too narrow.
Second, I fear that this definition is a reflection of products in the market today and not a statement on what “entitlement management” is meant to do. Yes, most of today’s products can use XACML. Yes, they facilitate authorization decisions based on a wider context. But who’s to say that these products, and the market as a whole, have reached their final state? Along these lines, I wonder if externalized authorization stores are a required part of an “entitlement management” solution?
Third, there is something missing from the definition – the policy enforcement point. A fine-grained authorization engine provides a policy decision point, but that still leaves the need for an enforcement point. This holds true whether an application has externalized its authorization decisions or not.