[cap-talk] Concening entry "ambient authority" in Wikipedia

[Toby Murray]

On Wed, 2009-06-10 at 16:29 +0200, Marcus Brinkmann wrote:
> Sandro Magi wrote:
> > Marcus Brinkmann wrote:
> >> I don't see how that follows.  In my mind, these undeniable capabilities are
> >> received by creation. 
> > 
> > Yes, but not *explicitly* received, they are *implicitly* received, and
> > thus cannot be denied or exchanged for arbitrary objects that you may
> > want to confine. This would preclude it from being an ocap system.
> 
> You can assume that I understood by now that this is what you want "ocap"
> system to mean.  Unfortunately, I can neither see this from the formal
> definition, nor can I imagine a real world system where the properties you
> desire exist, as I explained.
> 
> Is there a real world ocap system which allows to (at least at startup) deny
> or exchange the integer number "5"?
> 

Marcus makes a good point. Most if not all actual ocap systems
implicitly provide certain capabilities to all objects. However, they
are supposed to only provide (what I will here call) "ambient"
capabilities that confer no "real" authority (for some definition of
"real"). 

One characterisation of "real" is "If you didn't already have it, you
couldn't built it yourself." I can't think of a better one but one
probably exists.