Re: NEW ISSUE: (3622) Policy assertion equivalence and generality

On Aug 25, 2006, at 5:56 PM, Fabian Ritzmann wrote:

>
> Hi Bijan,
>
> Are you aware of Anne Anderson's work? She's designed a simple  
> language that is compatible with WS-Policy and seems to fit your  
> requirements:

We both presented at a workshop at WWW in Japan, so we know each  
other's work :)

> http://research.sun.com/projects/xacml/
>
> I'd suggest this paper for a quick introduction:
>
> http://research.sun.com/projects/xacml/POLICY06_paper.pdf

As I understand it, Anne's work (and XACML) addresses how to define  
the *assertions* in a common, evaluable, language. It's not clear to  
me that one can (easily) infer equivalence, for example, and one  
certainly can't do that if the equivalence is "semantic", that is, in  
the sense of saying that either of two distinct conditions "means"  
the same thing.

So, I think even there, having the ability to equate or relate  
assertions can be quite useful. In the context where the truth of the  
assertion is determined entirely out of band (as in WS-Policy), then  
it seems even more helpful.

The big advantage is being able to reason with policies even if one  
can't poke into an assertion.

But perhaps I'm wrong about Anne's work? I'll drop her a note  
pointing to this dicusssion.

Cheers,
Bijan.