Re: [DNSOP] Key sizes was Re: I-D Action:draft-ietf-dnsop-rfc4641bis-01.txt
Paul Wouters <paul@xelerance.com> Fri, 24 April 2009 20:02 UTC
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Date: Fri, 24 Apr 2009 16:03:24 -0400
From: Paul Wouters <paul@xelerance.com>
To: Evan Hunt <Evan_Hunt@isc.org>
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Cc: dnsop@ietf.org, Paul Hoffman <paul.hoffman@vpnc.org>, Shane Kerr <shane@ca.afilias.info>
Subject: Re: [DNSOP] Key sizes was Re: I-D Action:draft-ietf-dnsop-rfc4641bis-01.txt
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On Fri, 24 Apr 2009, Evan Hunt wrote: >> a) KSKs longer than ZSKs because KSKs are thought of as needing to be >> stronger >> >> b) KSKs the same strength as ZSKs because neither should be weak enough >> to be attacked >> >> I prefer (b), but (a) keeps coming up in this discussion. > > It's a little imprecise, but I'm inclined to think of key lifetime as an > aspect of key strength. A 1024-bit key that rolls over every week may be > "stronger", in a sense, than a 2048-bit key that stays around for twenty > years--the second one could be broken within its lifetime, the first one > probably not. But the essential part is that once you see, say after 10 years, that the KSK 2048 bit key comes into the "feasable but impractial" scale of things due to advacements in math or technology, that you can decided to roll it over fairly quickly. > IMHO it's reasonable to make recommendations with that tradeoff in mind; a > ZSK may be as long as a KSK, or it may be shorter if it's rolled over more > frequently. (I think 4641bis already says something along those lines.) What I was told by my "lunching cryptographer" was that 1024bits were more then enough even for multi year KSK's, assuming sining only, no encryption. >From a cryptography strength point of view, more is always better, but now you need to consider work done by you and resolvers, and space constrictions with the DNS packet size. I don't see a cryptographic reason for Paul Hoffman's "I'd like the keys to be of equal size". Unless you'd argue that the KSK could easilly also be 1024bit, and that the additional 11 months of validity of the KSK is negligable compared to the time now upto 3 years from now, to break a 1024 bit RSA key. Paul
- [DNSOP] I-D Action:draft-ietf-dnsop-rfc4641bis-01… Internet-Drafts
- Re: [DNSOP] I-D Action:draft-ietf-dnsop-rfc4641bi… Shane Kerr
- Re: [DNSOP] I-D Action:draft-ietf-dnsop-rfc4641bi… Edward Lewis
- Re: [DNSOP] I-D Action:draft-ietf-dnsop-rfc4641bi… Florian Weimer
- [DNSOP] HSMs was Re: I-D Action:draft-ietf-dnsop-… Edward Lewis
- Re: [DNSOP] HSMs was Re: I-D Action:draft-ietf-dn… Stephane Bortzmeyer
- Re: [DNSOP] HSMs was Re: I-D Action:draft-ietf-dn… Edward Lewis
- Re: [DNSOP] HSMs was Re: I-D Action:draft-ietf-dn… Andrew Sullivan
- Re: [DNSOP] HSMs was Re: I-D Action:draft-ietf-dn… Shane Kerr
- [DNSOP] Key sizes was Re: I-D Action:draft-ietf-d… Paul Hoffman
- Re: [DNSOP] Key sizes was Re: I-D Action:draft-ie… Edward Lewis
- Re: [DNSOP] HSMs was Re: I-D Action:draft-ietf-dn… Edward Lewis
- Re: [DNSOP] Key sizes was Re: I-D Action:draft-ie… Paul Hoffman
- Re: [DNSOP] HSMs was Re: I-D Action:draft-ietf-dn… Paul Wouters
- Re: [DNSOP] HSMs was Re: I-D Action:draft-ietf-dn… Paul Wouters
- Re: [DNSOP] HSMs was Re: I-D Action:draft-ietf-dn… Andrew Sullivan
- Re: [DNSOP] HSMs was Re: I-D Action:draft-ietf-dn… Shane Kerr
- Re: [DNSOP] Key sizes was Re: I-D Action:draft-ie… Shane Kerr
- Re: [DNSOP] HSMs was Re: I-D Action:draft-ietf-dn… Edward Lewis
- Re: [DNSOP] HSMs was Re: I-D Action:draft-ietf-dn… Edward Lewis
- Re: [DNSOP] Key sizes was Re: I-D Action:draft-ie… Paul Hoffman
- Re: [DNSOP] Key sizes was Re: I-D Action:draft-ie… Paul Wouters
- Re: [DNSOP] HSMs was Re: I-D Action:draft-ietf-dn… Paul Wouters
- Re: [DNSOP] Key sizes was Re: I-D Action:draft-ie… Shane Kerr
- Re: [DNSOP] Key sizes was Re: I-D Action:draft-ie… Chris Thompson
- Re: [DNSOP] Key sizes was Re: I-D Action:draft-ie… Paul Hoffman
- Re: [DNSOP] Key sizes was Re: I-D Action:draft-ie… Paul Wouters
- Re: [DNSOP] Key sizes was Re: I-D Action:draft-ie… Shane Kerr
- Re: [DNSOP] Key sizes was Re: I-D Action:draft-ie… Paul Wouters
- Re: [DNSOP] Key sizes was Re: I-D Action:draft-ie… Paul Hoffman
- Re: [DNSOP] Key sizes was Re: I-D Action:draft-ie… Jelte Jansen
- Re: [DNSOP] Key sizes was Re: I-D Action:draft-ie… Evan Hunt
- Re: [DNSOP] Key sizes was Re: I-D Action:draft-ie… Edward Lewis
- Re: [DNSOP] Key sizes was Re: I-D Action:draft-ie… Paul Wouters
- Re: [DNSOP] Key sizes was Re: I-D Action:draft-ie… Paul Wouters
- Re: [DNSOP] Key sizes was Re: I-D Action:draft-ie… Joe Abley
- Re: [DNSOP] Key sizes was Re: I-D Action:draft-ie… Paul Hoffman
- Re: [DNSOP] Key sizes was Re: I-D Action:draft-ie… Joe Abley
- Re: [DNSOP] Key sizes was Re: I-D Action:draft-ie… Paul Hoffman
- Re: [DNSOP] Key sizes was Re: I-D Action:draft-ie… Joe Abley
- Re: [DNSOP] Key sizes bmanning
- Re: [DNSOP] Key sizes was Re: I-D Action:draft-ie… Paul Hoffman
- Re: [DNSOP] Key sizes was Re: I-D Action:draft-ie… Paul Wouters
- Re: [DNSOP] Key sizes was Re: I-D Action:draft-ie… Ted Lemon
- Re: [DNSOP] Key sizes was Re: I-D Action:draft-ie… Joe Abley
- Re: [DNSOP] HSMs was Re: I-D Action:draft-ietf-dn… Peter Koch
- Re: [DNSOP] HSMs was Re: I-D Action:draft-ietf-dn… Edward Lewis
- Re: [DNSOP] HSMs was Re: I-D Action:draft-ietf-dn… Joe Abley
- Re: [DNSOP] HSMs was Re: I-D Action:draft-ietf-dn… Edward Lewis
- Re: [DNSOP] HSMs was Re: I-D Action:draft-ietf-dn… Paul Hoffman
- Re: [DNSOP] HSMs was Re: I-D Action:draft-ietf-dn… Francis Dupont
- Re: [DNSOP] HSMs was Re: I-D Action:draft-ietf-dn… Olaf Kolkman
- Re: [DNSOP] HSMs was Re: I-D Action:draft-ietf-dn… Richard Lamb
- Re: [DNSOP] HSMs was Re: I-D Action:draft-ietf-dn… Paul Wouters
- [DNSOP] rfc4641bis: NSEC vs NSEC3. Olaf Kolkman
- Re: [DNSOP] rfc4641bis: NSEC vs NSEC3. Mark Andrews
- Re: [DNSOP] rfc4641bis: NSEC vs NSEC3. Olaf Kolkman
- Re: [DNSOP] rfc4641bis: NSEC vs NSEC3. Alex Bligh
- Re: [DNSOP] rfc4641bis: NSEC vs NSEC3. Alex Bligh
- Re: [DNSOP] rfc4641bis: NSEC vs NSEC3. Paul Wouters
- Re: [DNSOP] rfc4641bis: NSEC vs NSEC3. Alex Bligh
- Re: [DNSOP] rfc4641bis: NSEC vs NSEC3. Edward Lewis
- Re: [DNSOP] rfc4641bis: NSEC vs NSEC3. Alex Bligh
- Re: [DNSOP] rfc4641bis: NSEC vs NSEC3. Paul Wouters
- Re: [DNSOP] rfc4641bis: NSEC vs NSEC3. Alex Bligh
- Re: [DNSOP] rfc4641bis: NSEC vs NSEC3. Alex Bligh
- Re: [DNSOP] rfc4641bis: NSEC vs NSEC3. Olafur Gudmundsson
- Re: [DNSOP] rfc4641bis: NSEC vs NSEC3. Alex Bligh
- Re: [DNSOP] rfc4641bis: NSEC vs NSEC3. Matt Larson
- Re: [DNSOP] rfc4641bis: NSEC vs NSEC3. bmanning
- Re: [DNSOP] rfc4641bis: NSEC vs NSEC3. Olaf Kolkman
- Re: [DNSOP] rfc4641bis: NSEC vs NSEC3. Paul Wouters
- Re: [DNSOP] rfc4641bis: NSEC vs NSEC3. Olaf Kolkman
- Re: [DNSOP] rfc4641bis: NSEC vs NSEC3. Paul Wouters
- Re: [DNSOP] rfc4641bis: NSEC vs NSEC3. W.C.A. Wijngaards
- Re: [DNSOP] rfc4641bis: NSEC vs NSEC3. Alex Bligh
- Re: [DNSOP] rfc4641bis: NSEC vs NSEC3. Olafur Gudmundsson
- Re: [DNSOP] rfc4641bis: NSEC vs NSEC3. Alex Bligh
- Re: [DNSOP] rfc4641bis: NSEC vs NSEC3. Paul Wouters
- Re: [DNSOP] rfc4641bis: NSEC vs NSEC3. Andrew Sullivan
- Re: [DNSOP] rfc4641bis: NSEC vs NSEC3. Evan Hunt
- Re: [DNSOP] rfc4641bis: NSEC vs NSEC3. Olafur Gudmundsson
- Re: [DNSOP] rfc4641bis: NSEC vs NSEC3. Todd Glassey
- Re: [DNSOP] rfc4641bis: NSEC vs NSEC3. John Dickinson
- Re: [DNSOP] rfc4641bis: NSEC vs NSEC3. Mark Andrews
- Re: [DNSOP] rfc4641bis: NSEC vs NSEC3. Roy Arends
- Re: [DNSOP] rfc4641bis: NSEC vs NSEC3. Eric Rescorla
- Re: [DNSOP] rfc4641bis: NSEC vs NSEC3. W.C.A. Wijngaards
- Re: [DNSOP] rfc4641bis: NSEC vs NSEC3. Roy Arends
- Re: [DNSOP] rfc4641bis: NSEC vs NSEC3. Roy Arends
- Re: [DNSOP] rfc4641bis: NSEC vs NSEC3. W.C.A. Wijngaards
- Re: [DNSOP] rfc4641bis: NSEC vs NSEC3. Roy Arends
- Re: [DNSOP] rfc4641bis: NSEC vs NSEC3. Alex Bligh
- Re: [DNSOP] rfc4641bis: NSEC vs NSEC3. Evan Hunt
- Re: [DNSOP] rfc4641bis: NSEC vs NSEC3. Matt Larson
- Re: [DNSOP] rfc4641bis: NSEC vs NSEC3. Edward Lewis
- Re: [DNSOP] rfc4641bis: NSEC vs NSEC3. Roy Arends
- Re: [DNSOP] rfc4641bis: NSEC vs NSEC3. Eric Rescorla
- Re: [DNSOP] rfc4641bis: NSEC vs NSEC3. Evan Hunt
- Re: [DNSOP] rfc4641bis: NSEC vs NSEC3. Todd Glassey
- Re: [DNSOP] rfc4641bis: NSEC vs NSEC3. Eric Rescorla
- Re: [DNSOP] rfc4641bis: NSEC vs NSEC3. Andrew Sullivan
- Re: [DNSOP] rfc4641bis: NSEC vs NSEC3. Alex Bligh
- Re: [DNSOP] rfc4641bis: NSEC vs NSEC3. Evan Hunt
- Re: [DNSOP] rfc4641bis: NSEC vs NSEC3. Eric Rescorla
- [DNSOP] threads having "jumped the shark" was Re:… Edward Lewis
- Re: [DNSOP] rfc4641bis: NSEC vs NSEC3. Jakob Schlyter
- Re: [DNSOP] rfc4641bis: NSEC vs NSEC3. Mark Andrews
- Re: [DNSOP] rfc4641bis: NSEC vs NSEC3. Mark Andrews
- Re: [DNSOP] rfc4641bis: NSEC vs NSEC3. Doug Barton
- Re: [DNSOP] rfc4641bis: NSEC vs NSEC3. Mark Andrews
- Re: [DNSOP] rfc4641bis: NSEC vs NSEC3. Mark Andrews
- Re: [DNSOP] rfc4641bis: NSEC vs NSEC3. Eric Rescorla
- Re: [DNSOP] rfc4641bis: NSEC vs NSEC3. Andrew Sullivan
- Re: [DNSOP] rfc4641bis: NSEC vs NSEC3. Roy Arends
- Re: [DNSOP] rfc4641bis: NSEC vs NSEC3. Roy Arends
- Re: [DNSOP] rfc4641bis: NSEC vs NSEC3. Mark Andrews
- Re: [DNSOP] rfc4641bis: NSEC vs NSEC3. Alex Bligh
- Re: [DNSOP] rfc4641bis: NSEC vs NSEC3. Doug Barton
- Re: [DNSOP] rfc4641bis: NSEC vs NSEC3. Florian Weimer
- Re: [DNSOP] rfc4641bis: NSEC vs NSEC3. Florian Weimer
- Re: [DNSOP] rfc4641bis: NSEC vs NSEC3. Olaf Kolkman
- Re: [DNSOP] rfc4641bis: NSEC vs NSEC3. Todd Glassey
- Re: [DNSOP] rfc4641bis: NSEC vs NSEC3. Paul Wouters
- Re: [DNSOP] rfc4641bis: NSEC vs NSEC3. Nicholas Weaver
- Re: [DNSOP] rfc4641bis: NSEC vs NSEC3. Paul Wouters
- Re: [DNSOP] rfc4641bis: NSEC vs NSEC3. Paul Wouters
- Re: [DNSOP] rfc4641bis: NSEC vs NSEC3. Paul Wouters
- Re: [DNSOP] rfc4641bis: NSEC vs NSEC3. Evan Hunt
- Re: [DNSOP] rfc4641bis: NSEC vs NSEC3. Roy Arends
- Re: [DNSOP] rfc4641bis: NSEC vs NSEC3. Roy Arends
- Re: [DNSOP] rfc4641bis: NSEC vs NSEC3. Doug Barton
- Re: [DNSOP] rfc4641bis: NSEC vs NSEC3. Paul Wouters
- Re: [DNSOP] rfc4641bis: NSEC vs NSEC3. Doug Barton