[cap-talk] Authority vs. Information Flow

[Toby Murray]

On Wed, 2008-02-13 at 08:41 -0800, Charles Landau wrote:
> At 4:19 PM +0000 2/13/08, Toby Murray wrote:
> >The question is "If Alice has authority over Bob,
> >does it follow that there exists an information flow from Alice to Bob?"
> 
> If Alice has read authority over Bob, the information flow is only in 
> the other direction.
> 
> >Example 2: In which Authority exists, but perhaps not Info Flow
> >---------------------------------------------------------------
> >
> >Now imagine the same scenario, except that now there is a third party,
> >Dave. Dave also has a button like Alice, that turns on the light in
> >Bob's room when it is pressed. Both Alice and Dave now have control over
> >the light.
> >
> >We presume further, that Bob's behaviour is fully specified and does not
> >permit the possibility that Bob
> 
> I think you mean Dave.

Absolutely. Thanks for pointing out the mistake.
> 
> >will refuse to push his button if Alice
> >hasn't already pushed hers. We make a symmetric assumption for Alice.
> >Whoever pushes their button first, then, causes the light to turn on.
> >
> >Both Alice and Dave now have authority to cause Bob to be able to see
> >the light turn on. But can either of them pass information to Bob?
> 
> There are techniques for passing information through noisy channels. 
> If you consider Alice to be the signal and Dave the noise, it should 
> still be possible to pass information in this case.

I tend to agree, on reflection. Thanks for the insight.


> _______________________________________________
> cap-talk mailing list
> cap-talk at mail.eros-os.org
> http://www.eros-os.org/mailman/listinfo/cap-talk