Re: [saag] AD review of draft-iab-crypto-alg-agility-06
Eliot Lear <lear@cisco.com> Thu, 03 September 2015 21:02 UTC
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To: Russ Housley <housley@vigilsec.com>
References: <55A938F1.9090404@cs.tcd.ie> <20150720044849.GY28047@mournblade.imrryr.org> <B866063D-C1A8-4286-83E1-9EBAE7994297@vigilsec.com> <55E83554.6010808@cisco.com> <62CBD9E2-2DB4-4D3D-93E5-ADEB0F3D3C12@vigilsec.com>
From: Eliot Lear <lear@cisco.com>
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Date: Thu, 03 Sep 2015 23:01:59 +0200
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Cc: saag@ietf.org
Subject: Re: [saag] AD review of draft-iab-crypto-alg-agility-06
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Much better. Eliot On 9/3/15 10:30 PM, Russ Housley wrote: > Eliot: > > We are talking about section 2.6... > >>> 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?). > Kathleen also had a comment on this part of the document in her IESG ballot. > > I'm trying to address both comments with this proposal: > > 2.6. Preserving Interoperability > > Cryptographic algorithm deprecation is very difficult. People do not > like to introduce interoperability problems, even to preserve > security. As a result, flawed algorithms are supported for far too > long. The impact of legacy software and long support tails on > security can be reduced by making it easy to transition from old > algorithms and suites to new ones. Social pressure is often needed > to cause the transition to happen. > > Implementers have been reluctant to remove deprecated algorithms or > suites from server software, and server administrators have been > reluctant to diable them over concerns that some party will no longer > have the ability to connect to their server. Implementers and > administrators want to improve security by using the best supported > algorithms, but their actions are tempered by the desire to preserve > connectivity. Recently, some browser vendors have started to provide > visual warnings when a deprecated algorithm or suite is used. These > visual warnings provide a new incentive to transition away from > deprecated algorithms and suites. > > Transition in Internet infrastructure is particularly difficult. The > digital signature on the certificate for an intermediate > certification authority (CA) [RFC5280] is often expected to last > decades, which hinders the transition away from a weak signature > algorithm or short key length. Once a long-lived certificate is > issued with a particular signature algorithm, that algorithm will be > used by many relying parties, and none of them can stop supporting it > without invalidating all of the subordinate certificates. In a > hierarchical system, many subordinate certificates could be impacted > by the decision to drop support for a weak signature algorithm or an > associated hash function. > > Institutions, being large or dominant users within a large user base, > can assist by coordinating the demise of an algorithm suite, making > the transition easier for their own users as well as others. > > Russ > >
- [saag] AD review of draft-iab-crypto-alg-agility-… Stephen Farrell
- Re: [saag] AD review of draft-iab-crypto-alg-agil… Paul Hoffman
- Re: [saag] AD review of draft-iab-crypto-alg-agil… Black, David
- Re: [saag] AD review of draft-iab-crypto-alg-agil… Kathleen Moriarty
- Re: [saag] AD review of draft-iab-crypto-alg-agil… Eliot Lear
- Re: [saag] AD review of draft-iab-crypto-alg-agil… Derek Atkins
- Re: [saag] AD review of draft-iab-crypto-alg-agil… Watson Ladd
- Re: [saag] AD review of draft-iab-crypto-alg-agil… Viktor Dukhovni
- Re: [saag] AD review of draft-iab-crypto-alg-agil… ianG
- Re: [saag] AD review of draft-iab-crypto-alg-agil… Black, David
- Re: [saag] AD review of draft-iab-crypto-alg-agil… Black, David
- Re: [saag] AD review of draft-iab-crypto-alg-agil… Viktor Dukhovni
- Re: [saag] AD review of draft-iab-crypto-alg-agil… Viktor Dukhovni
- Re: [saag] AD review of draft-iab-crypto-alg-agil… Nico Williams
- Re: [saag] AD review of draft-iab-crypto-alg-agil… Stephen Farrell
- Re: [saag] AD review of draft-iab-crypto-alg-agil… Viktor Dukhovni
- Re: [saag] AD review of draft-iab-crypto-alg-agil… Nico Williams
- Re: [saag] AD review of draft-iab-crypto-alg-agil… Nico Williams
- Re: [saag] AD review of draft-iab-crypto-alg-agil… Viktor Dukhovni
- Re: [saag] AD review of draft-iab-crypto-alg-agil… Stephen Farrell
- Re: [saag] AD review of draft-iab-crypto-alg-agil… Nico Williams
- Re: [saag] AD review of draft-iab-crypto-alg-agil… Viktor Dukhovni
- Re: [saag] AD review of draft-iab-crypto-alg-agil… Stephen Farrell
- Re: [saag] AD review of draft-iab-crypto-alg-agil… Stephen Farrell
- Re: [saag] AD review of draft-iab-crypto-alg-agil… Nico Williams
- Re: [saag] AD review of draft-iab-crypto-alg-agil… Stephen Farrell
- Re: [saag] AD review of draft-iab-crypto-alg-agil… Salz, Rich
- Re: [saag] AD review of draft-iab-crypto-alg-agil… Nico Williams
- Re: [saag] AD review of draft-iab-crypto-alg-agil… ianG
- Re: [saag] AD review of draft-iab-crypto-alg-agil… Viktor Dukhovni
- Re: [saag] AD review of draft-iab-crypto-alg-agil… Christian Huitema
- Re: [saag] AD review of draft-iab-crypto-alg-agil… Viktor Dukhovni
- Re: [saag] AD review of draft-iab-crypto-alg-agil… Kathleen Moriarty
- Re: [saag] AD review of draft-iab-crypto-alg-agil… Martin Thomson
- Re: [saag] AD review of draft-iab-crypto-alg-agil… Viktor Dukhovni
- Re: [saag] AD review of draft-iab-crypto-alg-agil… Salz, Rich
- Re: [saag] AD review of draft-iab-crypto-alg-agil… Kathleen Moriarty
- Re: [saag] AD review of draft-iab-crypto-alg-agil… Salz, Rich
- Re: [saag] AD review of draft-iab-crypto-alg-agil… Stephen Farrell
- Re: [saag] AD review of draft-iab-crypto-alg-agil… Viktor Dukhovni
- Re: [saag] AD review of draft-iab-crypto-alg-agil… Viktor Dukhovni
- Re: [saag] AD review of draft-iab-crypto-alg-agil… Salz, Rich
- Re: [saag] AD review of draft-iab-crypto-alg-agil… David Misell
- Re: [saag] AD review of draft-iab-crypto-alg-agil… Peter Gutmann
- Re: [saag] AD review of draft-iab-crypto-alg-agil… Viktor Dukhovni
- Re: [saag] AD review of draft-iab-crypto-alg-agil… Peter Gutmann
- Re: [saag] AD review of draft-iab-crypto-alg-agil… Viktor Dukhovni
- Re: [saag] AD review of draft-iab-crypto-alg-agil… Peter Gutmann
- Re: [saag] AD review of draft-iab-crypto-alg-agil… Salz, Rich
- Re: [saag] AD review of draft-iab-crypto-alg-agil… Viktor Dukhovni
- Re: [saag] AD review of draft-iab-crypto-alg-agil… Stephen Farrell
- Re: [saag] AD review of draft-iab-crypto-alg-agil… Salz, Rich
- Re: [saag] AD review of draft-iab-crypto-alg-agil… Kathleen Moriarty
- Re: [saag] AD review of draft-iab-crypto-alg-agil… Viktor Dukhovni
- Re: [saag] AD review of draft-iab-crypto-alg-agil… Viktor Dukhovni
- Re: [saag] AD review of draft-iab-crypto-alg-agil… Kathleen Moriarty
- Re: [saag] AD review of draft-iab-crypto-alg-agil… Martin Thomson
- Re: [saag] AD review of draft-iab-crypto-alg-agil… Viktor Dukhovni
- Re: [saag] AD review of draft-iab-crypto-alg-agil… Viktor Dukhovni
- Re: [saag] AD review of draft-iab-crypto-alg-agil… Yoav Nir
- Re: [saag] AD review of draft-iab-crypto-alg-agil… Stephen Farrell
- Re: [saag] AD review of draft-iab-crypto-alg-agil… Paterson, Kenny
- Re: [saag] AD review of draft-iab-crypto-alg-agil… Nico Williams
- Re: [saag] AD review of draft-iab-crypto-alg-agil… Stephen Farrell
- Re: [saag] AD review of draft-iab-crypto-alg-agil… Stephen Farrell
- Re: [saag] AD review of draft-iab-crypto-alg-agil… Paterson, Kenny
- Re: [saag] AD review of draft-iab-crypto-alg-agil… Peter Gutmann
- Re: [saag] AD review of draft-iab-crypto-alg-agil… Eliot Lear
- Re: [saag] AD review of draft-iab-crypto-alg-agil… Viktor Dukhovni
- Re: [saag] AD review of draft-iab-crypto-alg-agil… Nico Williams
- Re: [saag] AD review of draft-iab-crypto-alg-agil… Derek Atkins
- Re: [saag] AD review of draft-iab-crypto-alg-agil… Martin Thomson
- Re: [saag] AD review of draft-iab-crypto-alg-agil… Watson Ladd
- Re: [saag] AD review of draft-iab-crypto-alg-agil… Viktor Dukhovni
- Re: [saag] AD review of draft-iab-crypto-alg-agil… Martin Thomson
- Re: [saag] AD review of draft-iab-crypto-alg-agil… Salz, Rich
- Re: [saag] AD review of draft-iab-crypto-alg-agil… Joel Sing
- Re: [saag] AD review of draft-iab-crypto-alg-agil… Viktor Dukhovni
- Re: [saag] AD review of draft-iab-crypto-alg-agil… Russ Housley
- Re: [saag] AD review of draft-iab-crypto-alg-agil… Russ Housley
- Re: [saag] AD review of draft-iab-crypto-alg-agil… Viktor Dukhovni
- Re: [saag] AD review of draft-iab-crypto-alg-agil… Viktor Dukhovni
- Re: [saag] AD review of draft-iab-crypto-alg-agil… Eliot Lear
- Re: [saag] AD review of draft-iab-crypto-alg-agil… Eliot Lear
- Re: [saag] AD review of draft-iab-crypto-alg-agil… Russ Housley
- Re: [saag] AD review of draft-iab-crypto-alg-agil… Eliot Lear
- Re: [saag] AD review of draft-iab-crypto-alg-agil… Viktor Dukhovni
- Re: [saag] AD review of draft-iab-crypto-alg-agil… Russ Housley
- Re: [saag] AD review of draft-iab-crypto-alg-agil… Russ Housley
- Re: [saag] AD review of draft-iab-crypto-alg-agil… Salz, Rich
- Re: [saag] AD review of draft-iab-crypto-alg-agil… Viktor Dukhovni
- Re: [saag] AD review of draft-iab-crypto-alg-agil… Salz, Rich
- Re: [saag] AD review of draft-iab-crypto-alg-agil… Nico Williams
- Re: [saag] AD review of draft-iab-crypto-alg-agil… Christian Huitema
- Re: [saag] AD review of draft-iab-crypto-alg-agil… Viktor Dukhovni
- Re: [saag] AD review of draft-iab-crypto-alg-agil… Watson Ladd
- Re: [saag] AD review of draft-iab-crypto-alg-agil… Nico Williams
- Re: [saag] AD review of draft-iab-crypto-alg-agil… Viktor Dukhovni
- Re: [saag] AD review of draft-iab-crypto-alg-agil… Derek Atkins
- Re: [saag] AD review of draft-iab-crypto-alg-agil… Russ Housley
- Re: [saag] AD review of draft-iab-crypto-alg-agil… Russ Housley
- Re: [saag] AD review of draft-iab-crypto-alg-agil… Viktor Dukhovni
- Re: [saag] AD review of draft-iab-crypto-alg-agil… Russ Housley