At 08:13 PM 3/20/98 , William H. Geiger III wrote:
It is my position that algorithm preference is just that, a preference,
and the final desision of what algorithms to use should be the sole
decision of the owner of the document (ie the sender).
I think in a way one can have the best of both worlds. It's going to be a
question of user interface really.
Binding a list of accepted algorithms to one's public key is a "Good
Thing"(tm). What is a "Bad Thing"(tm) is having PGP on the sender's side
go through some required automated process in conventional cipher
selection. Ideally PGP should have a preference section which permits a
sender to be warned when encrypting to a key that does not have as its #1
preference the senders cipher of choice.
I look at this just like CMR keys. I have the option of being warned
before encrypting to one (presumably so I can decide NOT to encrypt to it
if I find it distasteful). If I find the cipher distasteful why should I
not be similarly warned?
"Warning: The holder of this public key has specified CAST as its
preferred cipher. CAST does not appear in your preferred cipher list. The
recipient also permits the use of 3DES, encrypt with this cipher instead?"
Caller ID was done much the same way. A call can be made with or without
sending caller ID info to the recipient, but the recipient has the option
of refusing to receive any calls which have first been *67'd.
This also begs for an interface which allows PGP to inform the user which
cipher received messages were encrypted with. I'm not aware that this is
possible now, and the interface by which I select which ciphers my key
accepts (you have to make the selections in a general preferences section
and then create a new key to impose those preferences).
I'm not sure this is spec stuff, but it seems to suggest that these issues
can be partly if not fully solved by user interface.
I suppose it would be nice to require more detailed sender notification of
the recipients cipher list.