Re: [saag] AD review of draft-iab-crypto-alg-agility-06

Eliot Lear <lear@cisco.com> Thu, 03 September 2015 11:56 UTC

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To: Russ Housley <housley@vigilsec.com>, saag@ietf.org
References: <55A938F1.9090404@cs.tcd.ie> <20150720044849.GY28047@mournblade.imrryr.org> <B866063D-C1A8-4286-83E1-9EBAE7994297@vigilsec.com>
From: Eliot Lear <lear@cisco.com>
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Date: Thu, 3 Sep 2015 13:56:04 +0200
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Subject: Re: [saag] AD review of draft-iab-crypto-alg-agility-06
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Hi Russ,

Just one comment:

On 9/2/15 10:48 PM, Russ Housley wrote:
> Merging with comments from others, the current text is:
>
>    Without clear mechanisms for algorithm and suite transition,
>    preserving interoperability becomes a difficult social problem.  For
>    example, consider web browsers.  Dropping support for an algorithm
>    suite can break connectivity to some web sites, and the browser
>    vendor will lose users by doing so.  This situation creates
>    incentives to support algorithm suites that would otherwise be
>    deprecated in order to preserve interoperability.

Honestly this paragraph is confusing.  It's opaque because it's not
clear whether you're aiming at a strawman of where TLS doesn't support
agility or the case of long lived root or intermediate certificates.  If
it's the former, can you find a more current example?  And the last
sentence is just flat out ambiguous, although in an amusing sort of way
(who deprecates in order to preserve interoperability?).

I can't propose replacement text here because of the ambiguities...

Eliot