Re: Policy equivalence [was: The Indeterminate flavors question]

[<remon.sinnema@emc.com>]

> -----Original Message-----
> From: Tyson, Paul H [mailto:PTyson@bellhelicopter.textron.com]
> Sent: Monday, April 25, 2011 3:22 PM
> To: Erik Rissanen; xacml
> Subject: RE: [xacml] The Indeterminate flavors question
> 
> In the longer term the TC should work out a comprehensive logical
> framework that explicitly either confirms or denies the "policy
> equivalence" (or "linearity" as Erik called it) between a policy with a
> non-empty target and the same policy with an empty target and the
> attribute tests distributed to the descendant conditions (with
> appropriate syntactic modifications).  Hal has said the TC has avoided
> previous attempts to define "policy equivalence", but I assume that was
> in general, not for this specific issue.

I agree that policy equivalence/linearity makes a lot of sense from the perspective of being able to understand XACML policies.
It might also enable certain optimizations in implementations.