Re: [TLS] Signature Algorithms

Dave Garrett <> Tue, 17 March 2015 17:41 UTC

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From: Dave Garrett <>
Date: Tue, 17 Mar 2015 13:41:39 -0400
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Subject: Re: [TLS] Signature Algorithms
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On Saturday, March 14, 2015 11:40:38 pm Mehner, Carl wrote:
> As we move into a world that lacks trusted SHA-1 signatures, a change in the text would be necessary in order for clients that drop SHA-1 from the supported hash algorithms to continue to connect to servers that send a certificate_list that includes roots signed with SHA-1.

What's the viability of having TLS 1.3 drop support for SHA-1 for end-entity certificates? (not root or intermediary, yet) This would of course be in addition to dropping all support for MD5, which I think is pretty much a given at this point.

If it were to be new policy right this second, that wouldn't be great, but by the time TLS 1.3 is ready for widespread adoption I think that's a reasonable expectation. Latest survey shows the SHA-1 to SHA-2 ratio at about 2:3 and improving steadily. SHA-2 will probably be used in the majority within a couple months or so.