Subject: Fwd: [Cfrg] target collisions and colliding certificates with different identities

From: Russ Housley <[email-masked]>
Date: Wed, 25 Oct 2006 14:21:36 -0400

FYI.

Please discuss on the CFRG list, but I thought the people on these 
lists would like to know about this research result.

Russ

>Date: Mon, 23 Oct 2006 23:58:21 +0200
>From: "Weger, B.M.M. de" <[email-masked]>
>To: <[email-masked]>,
>         <[email-masked]>,
>         <[email-masked]>
>Subject: [Cfrg] target collisions and colliding certificates with different
>         identities
>
>Hi all,
>
>We announce:
>- an example of a target collision for MD5; this means:
>   for two chosen messages m1 and m2 we have constructed
>   appendages b1 and b2 to make the messages collide
>   under MD5, i.e. MD5(m1||b1) = MD5(m2||b2);
>   said differently: we can cause an MD5 collision for
>   any pair of distinct IHVs;
>- an example of a pair of valid, unsuspicious X.509
>   certificates with distinct Distinguished Name fields,
>   but identical CA signatures; this example makes use
>   of the target collision.
>
>See http://www.win.tue.nl/hashclash/TargetCollidingCertificates/,
>where the certificates and a more detailed announcement
>can be found.
>
>Marc Stevens
>Arjen Lenstra
>Benne de Weger