> From: Bill Frantz [mailto:[EMAIL PROTECTED]]
> Sent: 27 July 1999 05:01
>
> >- how is it logically possible to PROVE non-possession of key?
>
> If you use a protocol which provides perfect forward
> security, then you can logically prove that you no longer have the key.
> The question is whether you can legally prove it.
Agreed - I really meant "logical" in the more philosophical sense - how DO
you show a key is not in your possession? Empty your pockets? Bang your fist
on your forehead in a manner calculated to convince a judge ?
Also, courts may be unwilling to believe that the sender hasn't somehow
doctored any purported PFS to save a key, or at least a record of the
plaintext.
It's also ominous for UK citizens that the same Minister proposing this is
also proposing to end the right of a defendant to a jury trial in certain
cases, which would include the "failing-to-comply" and "tipping-off"
offences. So it might literally be a case of tell-it-to-the-judge....
--
Caspar Bowden http://www.fipr.org
Director, Foundation for Information Policy Research
Tel: +44(0)171 354 2333 Fax: +44(0)171 827 6534