Re: A brief comparison of email encryption protocols

[Adam Shostack <adam@lighthouse.homeport.org>]

Eric Murray wrote:
| > 	key://foo.bar.com/{u,s,h,d}/family/instance
| While that would be useful in a lot of cases, I would hope that
| all that path gunk wouldn't be required.... most people would
| have one key, at least initially, and so a simple
| 
| key://foo.bar.com/username/key.asc
|
| would be enough for them.  I wouldn't want to prevent people
| from using your system, in fact it's a good idea.  I just don't think
| that it should be required, just recommended.
| Something else to add would be a specifier for the type of key, i.e.
| 
| key://slack.lne.com/pgp/ericm/key.asc

I'd either move that later in the structure, or leave it out.  Moving
it later in the structure so we don't need duplicate heirarchies.
Leaving it out may be ok because we can define a standard location by
key type: 

key://slack.lne.com/~ericm/key.asc
key://slack.lne.com/~ericm/key.x509

key://slack.lne.com/~ericm/x509/key.cert
key://slack.lne.com/~ericm/pgp/key.asc

I have no objection to defining a shorter URL, but would want some
indicator that we're in user space, not host/domain/realm space.  A
~username serves that purpose as well as /u/ and is a more common
usage.

My last comment is that if we define a URN scheme for keys, we should
force a dependable structure on it, so that its predictable where to
find a users PGP key from an email address, without having to check 6
locations.  Nothing is there now, we should require order to make
everyones life easier.

| Finally, a question:  should the keyserver be able to serve
| keys in a way that is secure from a MITM attack, or can it depend
| on the certificate chain in the key certificate itself to
| validate the key certificate?  I think it can, but I am not
| sure, so perhaps someone smarter than I can explain why, or why not.
|
| The attraction is obvious, if the key server doesn't have to
| validate the keys it serves, the whole problem of distributed
| key servers becomes much easier.

	A key server should serve keys because protecting from MITM is
hard.  Serving keys is easy, so we should solve that problem today,
and the other problems as we can.  Some infrastructure is better than
none.

Adam

-- 
"It is seldom that liberty of any kind is lost all at once."
					               -Hume