Comments on: Hidden Assumptions in Cryptographic Protocols http://www.lightbluetouchpaper.org/2009/02/02/hidden-assumptions-in-cryptographic-protocols/ Security Research, Computer Laboratory, University of Cambridge Fri, 10 Feb 2012 17:31:40 +0000 http://wordpress.org/?v=2.9.2 hourly 1 By: Steven J. Murdoch http://www.lightbluetouchpaper.org/2009/02/02/hidden-assumptions-in-cryptographic-protocols/comment-page-1/#comment-31067 Steven J. Murdoch Fri, 22 May 2009 09:27:28 +0000 http://www.lightbluetouchpaper.org/?p=657#comment-31067 This sort of problem comes up again and again. I found an instance of this flaw <a href="http://www.lightbluetouchpaper.org/2008/04/25/wordpress-25-cookie-integrity-protection-vulnerability/" rel="nofollow">in Wordpress</a>, and it is now revealed that even Amazon <a href="http://rdist.root.org/2009/05/20/amazon-web-services-signature-vulnerability/" rel="nofollow">slipped up</a>. Maybe HMAC have the wrong API; if the standard library call took a list of strings rather than a single one, and added separators unambiguously, these flaws would occur less often. This sort of problem comes up again and again. I found an instance of this flaw in Wordpress, and it is now revealed that even Amazon slipped up.

Maybe HMAC have the wrong API; if the standard library call took a list of strings rather than a single one, and added separators unambiguously, these flaws would occur less often.

]]> By: P http://www.lightbluetouchpaper.org/2009/02/02/hidden-assumptions-in-cryptographic-protocols/comment-page-1/#comment-30498 P Tue, 03 Feb 2009 18:40:36 +0000 http://www.lightbluetouchpaper.org/?p=657#comment-30498 http://jya.com/show-trials.htm The first one is a key I generated back in 1997 to demonstrate the fingerprint spoofing attack which results from the design mistake that the key component lengths are not included in the md5 hash whch forms the fingerprint in pgp2.x. The fingerprint attack details below [1] (btw. DO NOT USE THE KEY, the fingerprint attack makes it readable by anyone because of the small factors of the replacement N used). http://jya.com/show-trials.htm

The first one is a key I generated back in 1997 to demonstrate the fingerprint spoofing attack which results from the design mistake that the key component lengths are not included in the md5 hash whch forms the fingerprint in pgp2.x. The fingerprint attack details below [1] (btw. DO NOT USE THE KEY, the fingerprint attack makes it readable by anyone because of the small factors of the replacement N used).

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