[cap-talk] Non-safety vs. permission propagation

[Karp, Alan H]

Toby Murray wrote:

> Right. But as has been shown here, one can implement VOC on 
> top of a cap
> system. From memory MarcS has a "Non-Transferable Claim 
> Check" in E that
> does exactly this sort of thing somewhere in Walnut.
> 
Sorry for the late reply.  I set the note aside expecting MarkM to jump
in and then lost track of it.

E can implement only a part of VOC via the Loan Officer protocol.  (You
can borrow this money if you can prove you don't need it.)  In E that
translates to passing a capability as an argument only if the receiving
object alread has that capability.  VOC should also be able to prevent
the receiver from ever getting the right.

________________________
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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