[cap-talk] What's "Discretionary Security" (was: Another "core" principle, capability communication)

[Karp, Alan H]

MarkM wrote:
> 
> > Let's start with a plain conventional Unix ACL-ish example. 
> I create a file 
> > foo.txt. I choose not to give you write permission on this 
> file. Are we 
> > interacting using mandatory or discretionary security?
> 
> how would you describe it using these terms?
> 
Discretionary, but the example is flawed.  How can you choose to give a
subject write permission in a Unix system?  In a Unix-like system where
you can, it's non-discretionary if you want to grant write permission,
but the grantee doesn't get it.

Also, VOC is non-discretionary.

________________________
Alan Karp
Principal Scientist
Virus Safe Computing Initiative
Hewlett-Packard Laboratories
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