[cap-talk] Definition of a capability

[Karp, Alan H]

> -----Original Message-----
> Chip Morningstar wrote:
> 
> Hmmm.  I don't think that's right at all.  A capability certainly can
> depend on the the behavior of other objects -- the behavior 
> of the objects
> reachable by the object the capability designates, i.e., by 
> whatever authority
> the object designated by the capability chooses to make 
> available through the
> capability.  This is precisely the authority which the 
> capability grants.
> Saying that a capability combines designation with permission makes it
> impossible for us to talk about authority at all, since the 
> only means of
> transmission of authority from one object to another is via 
> capabilities.

But the capability itself only designates a specific object.  It is the
behavior of that object that can grant authority.  There's nothing about
that in the capability.
> 
> Also, I don't recall anyone ever saying that a capability 
> combines designation
> with authorization, I recall it as combining designation with 
> authority.
> Authorization and authority are not the same thing.  
> Authority is that which is
> authorized.

Point taken.
> 
> Chip
> 
________________________
Alan Karp
Principal Scientist
Virus Safe Computing Initiative
Hewlett-Packard Laboratories
1501 Page Mill Road
Palo Alto, CA 94304
(650) 857-3967, fax (650) 857-7029
https://ecardfile.com/id/Alan_Karp
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