Re: draft-ietf-openpgp-rfc2440bis-06.txt

Bodo Moeller <moeller@cdc.informatik.tu-darmstadt.de> Mon, 23 September 2002 19:04 UTC

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Date: Mon, 23 Sep 2002 20:57:29 +0200
From: Bodo Moeller <moeller@cdc.informatik.tu-darmstadt.de>
To: Richie Laager <rlaager@wiktel.com>
Cc: "'OpenPGP'" <ietf-openpgp@imc.org>
Subject: Re: draft-ietf-openpgp-rfc2440bis-06.txt
Message-ID: <20020923205729.A2899@cdc.informatik.tu-darmstadt.de>
References: <20020923200254.A3493@cdc.informatik.tu-darmstadt.de> <002301c26331$e9ffadb0$20a63992@umcrookston.edu>
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In-Reply-To: <002301c26331$e9ffadb0$20a63992@umcrookston.edu>; from rlaager@wiktel.com on Mon, Sep 23, 2002 at 01:49:14PM -0500
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On Mon, Sep 23, 2002 at 01:49:14PM -0500, Richie Laager wrote:

>> Did you read my original message from the mailing list archives?
>> There is a simple workaround for the protocol failure, which does
>> not have the problems of your proposal: whenever someone certifies
>> someone else's key, then if this key has an expiration time set,
>> the certification signature should get an expiration time too such
>> that the signature's validity period extends no longer into the
>> future than the key's validity period.

> How does this help? If a "bad guy" gets the private key, he can
> simply resign everyone's key.

If the bad guy gets Alice's private key that has expired, he can renew
Alice's self-signature on the key, but he cannot renew Bob's
certification for Alice's key, which will have expired too according
to my proposal.  So no-one will believe it is still Alice's key.

Well, nearly no-one -- I can't speak for Jon :-)


-- 
Bodo Möller <moeller@cdc.informatik.tu-darmstadt.de>;
PGP http://www.informatik.tu-darmstadt.de/TI/Mitarbeiter/moeller/0x36d2c658.html
* TU Darmstadt, Theoretische Informatik, Alexanderstr. 10, D-64283 Darmstadt
* Tel. +49-6151-16-6628, Fax +49-6151-16-6036