John and all,
I see that you didn't sent your keys to Harald? >;) That is a
definite
no no to him, and therefore you cannot be trusted in his eyes anyway
John.
I also heard that you finally decided the problem with Dennis S. MCI
software was as I indicated a MCI problem not his problem. A trust
issue perhaps, John? >;)
As for the rest of your comments, in general I agree.
John C Klensin wrote:
> For whatever it is worth, as someone who has been using PGP for
> many years and worrying about key integrity and validity and
> webs of trust for most of that time...
>
> (i) Mark's concerns about people signing things on the basis of
> faxed identity materials that can easily be tampered with are
> legitimate. One can debate about how often faked documents
> would actually appear in particular communities, but I would
> never sign a key on the basis of such a faxed document alone.
>
> (ii) The key to an operational "web of trust" is that word
> "trust". Using PGP in some of the arrangements that have been
> proposed would make me _lots_ happier than using email
> addresses, but, for digital signatures/ key certifications to be
> meaningful, one has to not only be able to authenticate the
> signer's key, but trust the signer to behave appropriately.
>
> (iii) Trust is a somewhat elusive concept. If the use of PGP
> signatures is going to be used to validate identity and
> uniqueness, then agreed-upon conventions are needed as to what
> gets signed and on what proofs. If the person doing the
> checking trusts the signer to have understood those conventions
> and followed them (and, incidentally, to be competent about key
> management), then the endorsement is useful. If not, it is
> meaningless (such an endorsement should not be held against the
> key-holder; to do so would enable all sorts of nasty attacks).
>
> (iv) Similarly, trust is not easily additive. One of the
> debates/difficulties in the PGP community for many years is how
> many "partially"-trusted signatures add up to one fully-trusted
> one. Some think the answer is two or three; others claim that
> no number will suffice. And some of us will make case-by-case
> decisions depending on the importance of what is happening. It
> is no accident that the programs have options to reflect all of
> those positions.
>
> The DNSO situation aside, different of us have different
> criteria for signing keys. If you see a key signed in one of
> my two main keys (one RSA, one DH/DSS), it implies that I've met
> the individual face to face, seen identification that I find
> satisfying, and gotten at least verbal confirmation of the key
> fingerprint from the keyholder. My criteria are not foolproof
> or attack-proof: I rarely take the extra step of sending someone
> an message encrypted in the public key they want me to sign and
> insist that they decrypt the message and send me back the secret
> contained therein before I will sign the key. Perhaps I should
> do so more often, but there are limits. Similarly, it would
> probably be possible to trick me by handing me a fake passport:
> I don't claim any knowledge of what most of the passports in the
> world look like or how to determine their validity. But a
> non-existent person would have to go to fairly extreme lengths
> to get me to sign a key (and I do keep an extra signing key,
> identified as lower confidence, around for when I need to
> endorse something but my normal criteria are not met).
>
> So, the "a group of bogus people get someone to sign all of
> their keys and the system breaks" should not be a plausible
> attack: if there are clear signing criteria, and they are
> reasonable, then someone who starts signing keys for non-people
> or on dubious authenticate goes on the "less trusted as signer"
> list and just doesn't count: people with keys signed by that
> individual would need to seek additional signatures elsewhere
> (not to increase the count, but to find a signature from a
> trusted signer).
>
> And, again, "not trusted" is a term of art here: I've worked
> with people whose identity I can vouch for, whose integrity I
> trust completely, but who are, by experience and demonstration,
> lousy key managers (typically because they don't understand the
> theory well enough to implement it faithfully). So I don't
> trust their signatures on other people's keys, not because I
> don't trust the people, but because I know of too many
> opportunities to compromise their keys. Life is hard sometimes.
>
> For completeness, the interesting attack by a collection of
> non-people wouldn't be to subvert one signer and get him or her
> to sign all of their keys. It would be to print up a
> collection of fake identification papers, one for each identity,
> but all bearing the same picture. The associated "face" and
> one of the sets of credentials would then be submitted to
> different potential trusted signers, so that each one would
> match a key, a name, identity papers, and a face and sign the
> relevant key. One would then have one real person (at most),
> associated with a number of (most faked) identities and keys
> with no easy detection mechanism. The latest versions of PGP
> permit including a signed, digitized, photograph with a public
> key, and that might help detect this particular fraud, but the
> formats involved are not backward-compatible and few of us are
> using them.
>
> john
>
> PGP Fingerprints:
> DH/DSS (id 0xB11F733D): DF70 5F40 B8C9 AE70 0B30 73C7 3E58
> E556 B11F 733D
> RSA (id 0x8F1B19A5): 6C84 7FC2 2F5A 2306 86BC DDE6 A573 E726
> Keys available from the usual servers.
Regards,
--
Jeffrey A. Williams
Spokesman INEGroup (Over 95k members strong!)
CEO/DIR. Internet Network Eng/SR. Java/CORBA Development Eng.
Information Network Eng. Group. INEG. INC.
E-Mail [EMAIL PROTECTED]
Contact Number: 972-447-1894
Address: 5 East Kirkwood Blvd. Grapevine Texas 75208
