[Wolves] PGP

[Stuart Langridge]

Peter Oliver wrote:
> On Thu, 12 Aug 2004, Jon Farmer wrote:
> 
>> ...a key holder is obliged to release the private key and any 
>> assoicated keys or passphrases [to the government]
> 
> And not tell anyone that they had to do so.

Not quite. You can decrypt the message and provide the decrypted 
plaintext; you are not obliged to give the Man your private key. 
Moreover, since a lot of stream communication which is "asymmetrically 
encrypted" is actually symmetrically encrypted with a session key (which 
was established and passed at the beginning of the conversation using 
public-key crypto), you can also pass PC Plod the session key. They did 
try and insist that Plod could demand anyone's private key, and that 
that person could not ever revoke that key (as that would be tantamount 
to admitting that Plod had it), and that Plod could keep it for ever, 
but fortunately the gummint were given the derriere velocite PDQ on that.

http://www.cs.man.ac.uk/~chl/scenarios.html is a bit out of date but 
still very instructive.

Aq.