Re: [CGA-EXT] WGLC for draft-ietf-csi-hash-threat-05.txt
Ana Kukec <anchie@fer.hr> Fri, 12 February 2010 13:50 UTC
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Date: Fri, 12 Feb 2010 14:51:29 +0100
From: Ana Kukec <anchie@fer.hr>
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To: Jean-Michel Combes <jeanmichel.combes@gmail.com>
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Cc: "cga-ext@ietf.org" <cga-ext@ietf.org>
Subject: Re: [CGA-EXT] WGLC for draft-ietf-csi-hash-threat-05.txt
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Hi Jean-Michel, Thanks for the comments, they are very useful. While addressing your comments in the new version of the draft, i noticed your question. Jean-Michel Combes wrote: > ... non-repudiation feature, while collision attacks are mainly about > affecting the non-repudiation feature, i.e. in the collision attack > against the CGA both of the CGA Parameters sets are choosen by an > attacker, which is not useful in the real-world scenarios. > > <JMC> > "which is not useful in the real-world scenarios" > Out of curiosity, may you explain to me why you have such a conclusion? > <JMC> > AFAIU, that conclusion is the consequence of two things: => CGA does is that it proves that the sender of the message is the same as the one from the previous message. => In the collision attack against CGA in SEND, the attacker itself produces both (colliding) CGAs and both sets of CGA Parameters sets. This basically means that CGAs do not deal with the non-repudiation. So, what are the benefits of such attack? I mean, CGA and SEND did what they were supposed to do, no matter of circumstances. Ana
- [CGA-EXT] WGLC for draft-ietf-csi-hash-threat-05.… marcelo bagnulo braun
- Re: [CGA-EXT] WGLC for draft-ietf-csi-hash-threat… Jean-Michel Combes
- [CGA-EXT] [Fwd: Re: WGLC for draft-ietf-csi-hash-… marcelo bagnulo braun
- Re: [CGA-EXT] [Fwd: Re: WGLC for draft-ietf-csi-h… Ana Kukec
- Re: [CGA-EXT] WGLC for draft-ietf-csi-hash-threat… Sheng Jiang
- Re: [CGA-EXT] WGLC for draft-ietf-csi-hash-threat… Ana Kukec