Re: [dnsext] DNSSEC, robustness, and several DS records

Doug Barton <> Thu, 12 May 2011 19:05 UTC

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Date: Thu, 12 May 2011 12:05:32 -0700
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Subject: Re: [dnsext] DNSSEC, robustness, and several DS records
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On 05/12/2011 07:35, Tony Finch wrote:
> W.C.A. Wijngaards<>  wrote:
>> The weakness in MD5 that I heard about (on slashdot I think) was that
>> you could construct data that matched a particular hash.
> No, it's a collision attack. You can construct two things with the same
> hash. You can't construct something to match a given hash.
> This discussion seems silly to me, given that SHA1 is not likely to be
> vulnerable for a long time, and we will be able to stop relying on it
> before attacks become practical. We can rely on sensible behaviour by
> hostmasters rather than building brittleness into the protocol.

Right, which, btw is an unstated assumption that I was making in my 
previous posts.

I fully agree that we need to move toward SHA-256. In fact in the past I 
advocated here that the dnssec-bis docs should eliminate SHA-1 
altogether, but I got shouted down out of respect for the "installed 
base" and deployment being "just around the corner." So if both work, 
sure, disregard SHA-1. Otherwise, go with what works.



	Nothin' ever doesn't change, but nothin' changes much.
			-- OK Go

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