[cap-talk] Confinement Confusion (was: Communicating conspirators)

[Mark S. Miller]

David Wagner wrote:
> Mark Miller writes:
>> I agree, but for the phrase "the *-property could also be viewed as an 
>> approach to achieving bit-confinement". If X is a necessary step for achieving 
>> Y, but not sufficient for achieving Y, then it seems strange and confusing to 
>> me to say that Y is an approach for achieving X.
> 
> It sounds like you are saying that the *-property is not sufficient
> to ensure bit-confinement.  Can you explain that?  As far as I know,
> if the *-property is faithfully followed at every level of the system,
> and applied to every system resource, then I suspect it is sufficient
> for bit-confinement (in the sense that High processes are confined and
> cannot leak bits to Low processes).  Is that not the case?

I agree that the *-properties imply bit confinement. Similarly, If X is a 
necessary step for achieving Y, then Y will imply X. If X not sufficient for 
achieving Y, and X is meaningful by itself, then I still find it strange to 
say that Y is an approach for achieving X. That seems backwards to me.

-- 
Text by me above is hereby placed in the public domain

     Cheers,
     --MarkM