Re: [Ace] Key IDs ... RE: WGLC on draft-ietf-ace-cwt-proof-of-possession-02
Jim Schaad <ietf@augustcellars.com> Tue, 26 June 2018 16:54 UTC
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From: Jim Schaad <ietf@augustcellars.com>
To: 'Benjamin Kaduk' <kaduk@mit.edu>, 'Hannes Tschofenig' <Hannes.Tschofenig@arm.com>
CC: 'Mike Jones' <Michael.Jones@microsoft.com>, draft-ietf-ace-cwt-proof-of-possession@ietf.org, ace@ietf.org
References: <VI1PR0801MB2112C4D6D3CED7C15D9AE886FA750@VI1PR0801MB2112.eurprd08.prod.outlook.com> <20180622204344.GP64617@kduck.kaduk.org> <MW2PR00MB02986BC1E87754046C8CDC6AF5750@MW2PR00MB0298.namprd00.prod.outlook.com> <20180623212956.GE99689@kduck.kaduk.org> <VI1PR0801MB2112F3791E8467A53C440E11FA490@VI1PR0801MB2112.eurprd08.prod.outlook.com> <20180626150003.GD79565@kduck.kaduk.org> <VI1PR0801MB2112F73E53F790A076D5FFEBFA490@VI1PR0801MB2112.eurprd08.prod.outlook.com> <20180626151415.GE79565@kduck.kaduk.org>
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Date: Tue, 26 Jun 2018 18:54:23 +0200
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Subject: Re: [Ace] Key IDs ... RE: WGLC on draft-ietf-ace-cwt-proof-of-possession-02
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No Ben, you are 100% correct. This is about identifiers and not session keys. > -----Original Message----- > From: Benjamin Kaduk <kaduk@mit.edu> > Sent: Tuesday, June 26, 2018 5:14 PM > To: Hannes Tschofenig <Hannes.Tschofenig@arm.com> > Cc: Mike Jones <Michael.Jones@microsoft.com>; Jim Schaad > <ietf@augustcellars.com>; draft-ietf-ace-cwt-proof-of-possession@ietf.org; > ace@ietf.org > Subject: Re: [Ace] Key IDs ... RE: WGLC on draft-ietf-ace-cwt-proof-of- > possession-02 > > I thought we were worried about collision of key *identifiers*, which were > not necessarily raw keys or hashes thereof. But it's possible I was not paying > enough attention and got confused. > > -Ben > > On Tue, Jun 26, 2018 at 03:12:52PM +0000, Hannes Tschofenig wrote: > > It does answer my question, Ben. > > > > This begs the question why the collision of session keys is suddenly a > problem in the ACE context when it wasn't a problem so far. Something must > have changed. > > > > Ciao > > Hannes > > > > > > -----Original Message----- > > From: Benjamin Kaduk [mailto:kaduk@mit.edu] > > Sent: 26 June 2018 17:00 > > To: Hannes Tschofenig > > Cc: Mike Jones; Jim Schaad; > > draft-ietf-ace-cwt-proof-of-possession@ietf.org; ace@ietf.org > > Subject: Re: [Ace] Key IDs ... RE: WGLC on > > draft-ietf-ace-cwt-proof-of-possession-02 > > > > On Tue, Jun 26, 2018 at 08:53:57AM +0000, Hannes Tschofenig wrote: > > > Ben, > > > > > > I was wondering whether the situation is any different in Kerberos. If the > KDC creates tickets with a session key included then it needs to make sure > that it does not create the same symmetric key for different usages. > > > The key in the Kerberos ticket is similar to the PoP key in our discussion. > > > > > > Are we aware of key collision in Kerberos? > > > > I don't believe key collision is an issue in Kerberos. Long-term keys > > (which are not what we're talking about here) are identified by a > > principal name, encryption type, and version number. Session keys > > that are contained within tickets (and returned to the client in the > > KDC-REP) are random, so even if we are only using the birthday bound > > we're still in pretty good shape. The modern enctypes tend to use > > subsession keys generated by the client and/or server as well as the > > KDC-generated session key, which provides further binding to the current > session. > > > > Does that answer your question? > > > > -Ben > > IMPORTANT NOTICE: The contents of this email and any attachments are > confidential and may also be privileged. If you are not the intended recipient, > please notify the sender immediately and do not disclose the contents to any > other person, use it for any purpose, or store or copy the information in any > medium. Thank you.
- Re: [Ace] Key IDs ... RE: WGLC on draft-ietf-ace-… Jim Schaad
- [Ace] Key IDs ... RE: WGLC on draft-ietf-ace-cwt-… Hannes Tschofenig
- Re: [Ace] Key IDs ... RE: WGLC on draft-ietf-ace-… Jim Schaad
- Re: [Ace] Key IDs ... RE: WGLC on draft-ietf-ace-… Hannes Tschofenig
- Re: [Ace] Key IDs ... RE: WGLC on draft-ietf-ace-… Hannes Tschofenig
- Re: [Ace] Key IDs ... RE: WGLC on draft-ietf-ace-… Jim Schaad
- Re: [Ace] Key IDs ... RE: WGLC on draft-ietf-ace-… Jim Schaad
- Re: [Ace] Key IDs ... RE: WGLC on draft-ietf-ace-… Benjamin Kaduk
- Re: [Ace] Key IDs ... RE: WGLC on draft-ietf-ace-… Hannes Tschofenig
- Re: [Ace] Key IDs ... RE: WGLC on draft-ietf-ace-… Hannes Tschofenig
- Re: [Ace] Key IDs ... RE: WGLC on draft-ietf-ace-… Benjamin Kaduk
- Re: [Ace] Key IDs ... RE: WGLC on draft-ietf-ace-… Hannes Tschofenig
- Re: [Ace] Key IDs ... RE: WGLC on draft-ietf-ace-… Benjamin Kaduk
- Re: [Ace] Key IDs ... RE: WGLC on draft-ietf-ace-… Hannes Tschofenig
- Re: [Ace] Key IDs ... RE: WGLC on draft-ietf-ace-… Ludwig Seitz
- Re: [Ace] Key IDs ... RE: WGLC on draft-ietf-ace-… Benjamin Kaduk
- Re: [Ace] Key IDs ... RE: WGLC on draft-ietf-ace-… Mike Jones
- Re: [Ace] Key IDs ... RE: WGLC on draft-ietf-ace-… Jim Schaad
- Re: [Ace] Key IDs ... RE: WGLC on draft-ietf-ace-… Jim Schaad
- Re: [Ace] Key IDs ... RE: WGLC on draft-ietf-ace-… Mike Jones
- Re: [Ace] Key IDs ... RE: WGLC on draft-ietf-ace-… Samuel Erdtman
- Re: [Ace] Key IDs ... RE: WGLC on draft-ietf-ace-… Jim Schaad
- Re: [Ace] Key IDs ... RE: WGLC on draft-ietf-ace-… Jim Schaad
- Re: [Ace] Key IDs ... RE: WGLC on draft-ietf-ace-… Mike Jones
- Re: [Ace] Key IDs ... RE: WGLC on draft-ietf-ace-… Benjamin Kaduk
- Re: [Ace] Key IDs ... RE: WGLC on draft-ietf-ace-… Samuel Erdtman
- Re: [Ace] Key IDs ... RE: WGLC on draft-ietf-ace-… Samuel Erdtman
- Re: [Ace] Key IDs ... RE: WGLC on draft-ietf-ace-… Jim Schaad
- Re: [Ace] Key IDs ... RE: WGLC on draft-ietf-ace-… Ludwig Seitz
- Re: [Ace] Key IDs ... RE: WGLC on draft-ietf-ace-… Ludwig Seitz
- Re: [Ace] Key IDs ... RE: WGLC on draft-ietf-ace-… Mike Jones