Difference between TCPA-Hardware and other forms of trust

[Bill Frantz]

At 7:30 AM -0800 12/17/03, Jerrold Leichter wrote:
>
>...
>
>If the system were really trusted, it could store things like your credit
>balance:  A vendor would trust your system's word about the contents, because
>even you would not be able to modify the value.  This is what smart cards
>attempt to offer - and, again, it would be really nice if you didn't have to
>have a whole bunch of them.  The bank records stored on your system could
>be trusted:  By the bank, by you - and, perhaps quite useful to you, by a
>court if you claimed that the bank's records had been altered.

One should note that TCPA is designed to store its data (encrypted) in the
standard file system, so standard backup and restore techniques can be
used.  However, being able to backup my bank balance, buy a bunch of neat
stuff, and then restore the previous balance is not really what a banking
application wants.  Smart cards address this situation by storing the data
on the card, which is designed to be difficult to duplicate.

[I always considered the biggest contribution from Mondex was the idea of
deposit-only purses, which might reduce the incentive to rob late-night
business.]

Cheers - Bill



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Bill Frantz        | "There's nothing so clear as a | Periwinkle
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