Re: [TLS] Do we need DH?

Nico Williams <nico@cryptonector.com> Fri, 02 January 2015 17:17 UTC

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Date: Fri, 02 Jan 2015 11:17:15 -0600
From: Nico Williams <nico@cryptonector.com>
To: Yoav Nir <ynir.ietf@gmail.com>
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Subject: Re: [TLS] Do we need DH?
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On Fri, Jan 02, 2015 at 03:08:07PM +0200, Yoav Nir wrote:
> > On Jan 2, 2015, at 2:46 PM, Hubert Kario <hkario@redhat.com> wrote:
> > On Tuesday 30 December 2014 09:23:22 Tapio Sokura wrote:
> >> With regards to all eggs being in the same basket, AES is also something
> >> that really should have a realistic alternative standardized and
> >> deployed _before_ (/if) AES is broken. Like SHA-3 is coming around the
> >> corner while SHA-2 is still well alive and kicking.
> > 
> > We do have Camellia ciphers defined, PFS AEAD included (RFC 6367).
> 
> That, and the ChaCha20+Poly1305 AEAD will be defined when http://tools.ietf.org/html/draft-mavrogiannopoulos-chacha-tls-04 is adopted.

I think Hubert may be referring to the need for for interoperable
alternatives.  As in: being likely to find those alternatives deployed.

IOW, we need at least two realistic *REQUIRED to implement* algorithms
(curves for ECC) of most kinds: two hash functions, two PRFs, two ECDH
curves, two digital signature algorithms (e.g., RSA and E*DSA), two AEAD
ciphers.

For some kinds of algorithms (ciphers) this might be difficult,
politically.  But it's worth considering.

Nico
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