Re: [TLS] Adoption call for Deprecating FFDH(E) Ciphersuites in TLS

Carrick Bartle <cbartle891@icloud.com> Fri, 30 July 2021 20:25 UTC

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From: Carrick Bartle <cbartle891@icloud.com>
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Date: Fri, 30 Jul 2021 13:25:10 -0700
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To: Martin Thomson <mt@lowentropy.net>
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Subject: Re: [TLS] Adoption call for Deprecating FFDH(E) Ciphersuites in TLS
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Hi Martin,

Actually, a clarification question (more relevant to the other thread <https://mailarchive.ietf.org/arch/browse/tls/?q=Adoption%20call%20for%20Deprecating%20Obsolete%20Key%20Exchange%20Methods%20in%20TLS> : are you opposed to fully deprecating FFDHE? If so, why?


> On Jul 29, 2021, at 5:41 PM, Martin Thomson <mt@lowentropy.net> wrote:
> 
> I support the *contents* of this document.  The title, however, I can't agree to.  So I want to be clear about the scope of the work, namely deprecating semi-static FFDH and ECDH suites and any use of FFDHE ephemeral suites with reused keys.
> 
> The draft limits the ban on ephemeral key reuse to FFDHE, which is right; I could tolerate a prohibition on reuse for ECDH, but I know that we rely on that for HPKE and other things, so it can't really be bad enough to ban.
> 
> Cheers,
> Martin
> 
> On Fri, Jul 30, 2021, at 07:50, Joseph Salowey wrote:
>> This is a working group call for adoption for Deprecating FFDH(E) 
>> Ciphersuites in TLS (draft-bartle-tls-deprecate-ffdhe-00 
>> <https://datatracker.ietf.org/doc/draft-bartle-tls-deprecate-ffdhe/ <https://datatracker.ietf.org/doc/draft-bartle-tls-deprecate-ffdhe/>>). 
>> We had a presentation for this draft at the IETF 110 meeting and since 
>> it is a similar topic to the key exchange deprecation draft the chairs 
>> want to get a sense if the working group wants to adopt this draft 
>> (perhaps the drafts could be merged if both move forward).  Please 
>> review the draft and post your comments to the list by Friday, August 
>> 13, 2021.  
>> 
>> Thanks,
>> 
>> The TLS chairs
>> _______________________________________________
>> TLS mailing list
>> TLS@ietf.org
>> https://www.ietf.org/mailman/listinfo/tls
>> 
> 
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