Re: Factory Pitfall Ben Laurie (ben@algroup.co.uk)
Thu, 24 Dec 1998 10:43:09 +0000

Norman Hardy wrote:
>
> There is an avoidable pitfall in Factory usage.
> The requester passes in a spacebank and if
> that space bank buys and sells material from a general pool
> (which is the current normal practice) than an unconfined
> accomplice can obsereve the waxing and wayning of storage
> and thus receive signals from code within the confined
> environment. Banks can be configured to limit this
> effect to zero or near zero at fairly small storage cost.
>
> This "covert channel" was found by preliminary formal
> security analysis.

Hmmm ... do you think it is possible to avoid covert channels?

Cheers,

Ben.

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