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Re: PGP Signatures security BUG!
From: wprice () CYPHERS NET (Will Price)
Date: Mon, 20 Mar 2000 23:57:01 -0800

Hash: SHA1

We have researched this issue and discovered that in fact it was
caused by a problem with the machine running the primary keyserver at
certserver.pgp.com which resulted in a corrupt database.  The corrupt
database was then handing out the wrong key for a few of the keys
(there are about 1 million keys in the database).  The database has
been rebuilt and the responses are now correct in all cases.

Note that no security flaw was ever extant here.  No signature was
ever incorrectly identified by PGP as valid.  No key ID collision
occurred.  As mentioned by other posters, had a key ID collision
occurred, the effect would be harmless because the collision key
would not be valid.

Florian Weimer wrote:

"Povl H. Pedersen" <pope () NETGUIDE DK> writes:

This was the first time he verified it.

The signature has Key ID: 0x6F620B65

So he had to look up the key using the keyservers, and
surprisingly enough, the server did NOT return the name of the
sender, but of a person called "Mike Evans".

Several answers in this thread have addressed quite a few problems
regarding faked user IDs and key IDs.  This kind of attack is a
significant threat only if you rely on this information to
establish the validity of a public key, but of course, this
approach is
fundamentally flawed.

The problem that Povl observed was likely quite different.
According to my own attempts, NAI's server simply returned the
wrong key, which didn't share any obvious characteristics with the
one which was
requested (both key ID and user ID were different).  Currently, I'm
unable to reproduce the server behavior, though.

- --

Will Price, Director of Engineering
PGP Security, Inc.
a division of Network Associates, Inc.

Version: PGP 7.0 (Build 141 Alpha)


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