Re: [TLS] Security review of TLS1.3 0-RTT
Viktor Dukhovni <ietf-dane@dukhovni.org> Thu, 04 May 2017 00:51 UTC
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From: Viktor Dukhovni <ietf-dane@dukhovni.org>
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Date: Wed, 03 May 2017 20:51:37 -0400
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Subject: Re: [TLS] Security review of TLS1.3 0-RTT
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> On May 3, 2017, at 6:29 PM, Colm MacCárthaigh <colm@allcosts.net> wrote: > > Pervasive forward secrecy is one of the central security goals of modern > cryptography, Sure, given a sensible definition of forward-secrecy. And near instanenous deletion of session keys is not part of such a definition. > STEKs aren't compatible with this goal. They may be acceptable operationally > today, but I think they must be borrowed time if the central goal is meaningful. We need to recall what thread-model is behind the desire for forward-secrecy. It is I think not controversial to say that forward is concerned with limiting the damage from end-point (especially server end-point) compromise, in which confidentiality of long-term keys (still held on the endpoint) is lost. Consider the fact that such compromise is unlikely to be detected and remediated instantaneously. Indeed not only will the adversary have access for some time to sessions initiated post-compromise, he will also be able to impersonate the real server after the server is "secured" because certificate revocation will take days (or until the certificate expires) to take effect and more sessions can be compromised via MiTM attacks after the keys stolen. The incremental exposure of some fraction of a hour of sessions shortly before compromise pales in comparison with the much longer post-compromise exposure before the service is again secure. STEKs are simpler to design and secure than a complex session cache. This simplicity has security benefits. Properly implemented STEKS have a lifetime that is much shorter than any plausible compromise exposure time window. Given this, it makes sense to not consider potential STEK compromise as loss of forward secrecy. Forward secrecy guards against disclosure of truly long-term key material, with a lifetime of weeks to years. Once we get down to hours or minutes, it is quite sensible to take a coarser view of time, with similar exposure for sessions "just before" and "just after" compromise. Maximally sensitive traffic can take the penalty of avoiding session caching of any kind. -- Viktor.
- Re: [TLS] Security review of TLS1.3 0-RTT Colm MacCárthaigh
- [TLS] Security review of TLS1.3 0-RTT Colm MacCárthaigh
- Re: [TLS] Security review of TLS1.3 0-RTT Viktor Dukhovni
- Re: [TLS] Security review of TLS1.3 0-RTT Nico Williams
- Re: [TLS] Security review of TLS1.3 0-RTT Nico Williams
- Re: [TLS] Security review of TLS1.3 0-RTT Colm MacCárthaigh
- Re: [TLS] Security review of TLS1.3 0-RTT Nico Williams
- Re: [TLS] Security review of TLS1.3 0-RTT Viktor Dukhovni
- Re: [TLS] Security review of TLS1.3 0-RTT Colm MacCárthaigh
- Re: [TLS] Security review of TLS1.3 0-RTT Nico Williams
- Re: [TLS] Security review of TLS1.3 0-RTT Colm MacCárthaigh
- Re: [TLS] Security review of TLS1.3 0-RTT Nico Williams
- Re: [TLS] Security review of TLS1.3 0-RTT Viktor Dukhovni
- Re: [TLS] Security review of TLS1.3 0-RTT Benjamin Kaduk
- Re: [TLS] Security review of TLS1.3 0-RTT Colm MacCárthaigh
- Re: [TLS] Security review of TLS1.3 0-RTT Colm MacCárthaigh
- Re: [TLS] Security review of TLS1.3 0-RTT Ilari Liusvaara
- Re: [TLS] Security review of TLS1.3 0-RTT Viktor Dukhovni
- Re: [TLS] Security review of TLS1.3 0-RTT Benjamin Kaduk
- Re: [TLS] Security review of TLS1.3 0-RTT Nico Williams
- Re: [TLS] Security review of TLS1.3 0-RTT Benjamin Kaduk
- Re: [TLS] Security review of TLS1.3 0-RTT Nico Williams
- Re: [TLS] Security review of TLS1.3 0-RTT Benjamin Kaduk
- Re: [TLS] Security review of TLS1.3 0-RTT Nico Williams
- Re: [TLS] Security review of TLS1.3 0-RTT Daniel Kahn Gillmor
- Re: [TLS] Security review of TLS1.3 0-RTT Colm MacCárthaigh
- Re: [TLS] Security review of TLS1.3 0-RTT Nico Williams
- Re: [TLS] Security review of TLS1.3 0-RTT Eric Rescorla
- Re: [TLS] Security review of TLS1.3 0-RTT Nico Williams
- Re: [TLS] Security review of TLS1.3 0-RTT Eric Rescorla
- Re: [TLS] Security review of TLS1.3 0-RTT Peter Gutmann
- Re: [TLS] Security review of TLS1.3 0-RTT Colm MacCárthaigh
- Re: [TLS] Security review of TLS1.3 0-RTT Viktor Dukhovni
- Re: [TLS] Security review of TLS1.3 0-RTT Colm MacCárthaigh
- Re: [TLS] Security review of TLS1.3 0-RTT Jeffrey Walton
- Re: [TLS] Security review of TLS1.3 0-RTT Eric Rescorla
- Re: [TLS] Security review of TLS1.3 0-RTT Viktor Dukhovni
- Re: [TLS] Security review of TLS1.3 0-RTT Nico Williams
- Re: [TLS] Security review of TLS1.3 0-RTT Nico Williams
- Re: [TLS] Security review of TLS1.3 0-RTT Nico Williams
- Re: [TLS] Security review of TLS1.3 0-RTT Nico Williams
- Re: [TLS] Security review of TLS1.3 0-RTT Eric Rescorla
- Re: [TLS] Security review of TLS1.3 0-RTT Colm MacCárthaigh
- Re: [TLS] Security review of TLS1.3 0-RTT Martin Thomson
- Re: [TLS] Security review of TLS1.3 0-RTT Hannes Tschofenig
- Re: [TLS] Security review of TLS1.3 0-RTT Colm MacCárthaigh
- Re: [TLS] Security review of TLS1.3 0-RTT Viktor Dukhovni
- Re: [TLS] Security review of TLS1.3 0-RTT Colm MacCárthaigh
- Re: [TLS] Security review of TLS1.3 0-RTT Salz, Rich
- Re: [TLS] Security review of TLS1.3 0-RTT Viktor Dukhovni
- Re: [TLS] Security review of TLS1.3 0-RTT Salz, Rich
- Re: [TLS] Security review of TLS1.3 0-RTT Viktor Dukhovni
- Re: [TLS] Security review of TLS1.3 0-RTT Salz, Rich
- Re: [TLS] Security review of TLS1.3 0-RTT Nico Williams
- Re: [TLS] Security review of TLS1.3 0-RTT Viktor Dukhovni
- Re: [TLS] Security review of TLS1.3 0-RTT Nico Williams
- Re: [TLS] Security review of TLS1.3 0-RTT Timothy Jackson
- Re: [TLS] Security review of TLS1.3 0-RTT Viktor Dukhovni
- Re: [TLS] Security review of TLS1.3 0-RTT Colm MacCárthaigh
- Re: [TLS] Security review of TLS1.3 0-RTT Nico Williams
- Re: [TLS] Security review of TLS1.3 0-RTT Colm MacCárthaigh
- Re: [TLS] Security review of TLS1.3 0-RTT Viktor Dukhovni
- Re: [TLS] Security review of TLS1.3 0-RTT Colm MacCárthaigh
- Re: [TLS] Security review of TLS1.3 0-RTT Nico Williams
- Re: [TLS] Security review of TLS1.3 0-RTT Colm MacCárthaigh
- Re: [TLS] Security review of TLS1.3 0-RTT Viktor Dukhovni
- Re: [TLS] Security review of TLS1.3 0-RTT Colm MacCárthaigh
- Re: [TLS] Security review of TLS1.3 0-RTT Martin Thomson
- Re: [TLS] Security review of TLS1.3 0-RTT Colm MacCárthaigh
- Re: [TLS] Security review of TLS1.3 0-RTT Viktor Dukhovni
- Re: [TLS] Security review of TLS1.3 0-RTT Bill Cox
- Re: [TLS] Security review of TLS1.3 0-RTT Martin Thomson
- Re: [TLS] Security review of TLS1.3 0-RTT Colm MacCárthaigh
- Re: [TLS] Security review of TLS1.3 0-RTT Viktor Dukhovni
- Re: [TLS] Security review of TLS1.3 0-RTT Colm MacCárthaigh
- Re: [TLS] Security review of TLS1.3 0-RTT Watson Ladd
- Re: [TLS] Security review of TLS1.3 0-RTT Martin Thomson
- Re: [TLS] Security review of TLS1.3 0-RTT Viktor Dukhovni
- Re: [TLS] Security review of TLS1.3 0-RTT Salz, Rich
- Re: [TLS] Security review of TLS1.3 0-RTT Colm MacCárthaigh
- Re: [TLS] Security review of TLS1.3 0-RTT Colm MacCárthaigh
- Re: [TLS] Security review of TLS1.3 0-RTT Viktor Dukhovni
- Re: [TLS] Security review of TLS1.3 0-RTT Colm MacCárthaigh
- Re: [TLS] Security review of TLS1.3 0-RTT Blumenthal, Uri - 0553 - MITLL
- Re: [TLS] Security review of TLS1.3 0-RTT Eric Rescorla
- Re: [TLS] Security review of TLS1.3 0-RTT Peter Gutmann
- Re: [TLS] Security review of TLS1.3 0-RTT Colm MacCárthaigh
- Re: [TLS] Security review of TLS1.3 0-RTT Eric Rescorla
- Re: [TLS] Security review of TLS1.3 0-RTT Ilari Liusvaara
- Re: [TLS] Security review of TLS1.3 0-RTT Andrei Popov
- Re: [TLS] Security review of TLS1.3 0-RTT Colm MacCárthaigh
- Re: [TLS] Security review of TLS1.3 0-RTT Andrei Popov
- Re: [TLS] Security review of TLS1.3 0-RTT Colm MacCárthaigh
- Re: [TLS] Security review of TLS1.3 0-RTT Andrei Popov
- Re: [TLS] Security review of TLS1.3 0-RTT Colm MacCárthaigh
- Re: [TLS] Security review of TLS1.3 0-RTT Andrei Popov
- Re: [TLS] Security review of TLS1.3 0-RTT Erik Nygren
- Re: [TLS] Security review of TLS1.3 0-RTT Nico Williams
- Re: [TLS] Security review of TLS1.3 0-RTT Benjamin Kaduk
- Re: [TLS] Security review of TLS1.3 0-RTT Nico Williams
- Re: [TLS] Security review of TLS1.3 0-RTT Ilari Liusvaara
- Re: [TLS] Security review of TLS1.3 0-RTT Nico Williams
- Re: [TLS] Security review of TLS1.3 0-RTT Nico Williams
- Re: [TLS] Security review of TLS1.3 0-RTT Colm MacCárthaigh
- Re: [TLS] Security review of TLS1.3 0-RTT Colm MacCárthaigh
- Re: [TLS] Security review of TLS1.3 0-RTT Nico Williams
- Re: [TLS] Security review of TLS1.3 0-RTT Eric Rescorla
- Re: [TLS] Security review of TLS1.3 0-RTT Kyle Nekritz
- Re: [TLS] Security review of TLS1.3 0-RTT Eric Rescorla
- Re: [TLS] Security review of TLS1.3 0-RTT Nico Williams
- Re: [TLS] Security review of TLS1.3 0-RTT Erik Nygren
- Re: [TLS] Security review of TLS1.3 0-RTT Eric Rescorla
- Re: [TLS] Security review of TLS1.3 0-RTT Kyle Nekritz
- Re: [TLS] Security review of TLS1.3 0-RTT Derrell Piper
- Re: [TLS] Security review of TLS1.3 0-RTT Colm MacCárthaigh
- Re: [TLS] Security review of TLS1.3 0-RTT Benjamin Kaduk
- Re: [TLS] Security review of TLS1.3 0-RTT Eric Rescorla
- Re: [TLS] Security review of TLS1.3 0-RTT Ilari Liusvaara
- Re: [TLS] Security review of TLS1.3 0-RTT Nico Williams
- Re: [TLS] Security review of TLS1.3 0-RTT Christian Huitema
- Re: [TLS] Security review of TLS1.3 0-RTT Eric Rescorla
- Re: [TLS] Security review of TLS1.3 0-RTT Viktor Dukhovni
- Re: [TLS] Security review of TLS1.3 0-RTT Eric Rescorla
- Re: [TLS] Security review of TLS1.3 0-RTT Ilari Liusvaara
- Re: [TLS] Security review of TLS1.3 0-RTT Colm MacCárthaigh
- Re: [TLS] Security review of TLS1.3 0-RTT Ilari Liusvaara
- Re: [TLS] Security review of TLS1.3 0-RTT Eric Rescorla
- Re: [TLS] Security review of TLS1.3 0-RTT Colm MacCárthaigh
- Re: [TLS] Security review of TLS1.3 0-RTT Colm MacCárthaigh
- Re: [TLS] Security review of TLS1.3 0-RTT David Benjamin
- Re: [TLS] Security review of TLS1.3 0-RTT Viktor Dukhovni
- Re: [TLS] Security review of TLS1.3 0-RTT Colm MacCárthaigh
- Re: [TLS] Security review of TLS1.3 0-RTT Eric Rescorla
- Re: [TLS] Security review of TLS1.3 0-RTT Ilari Liusvaara
- Re: [TLS] Security review of TLS1.3 0-RTT Ilari Liusvaara
- Re: [TLS] Security review of TLS1.3 0-RTT Eric Rescorla
- Re: [TLS] Security review of TLS1.3 0-RTT Colm MacCárthaigh
- Re: [TLS] Security review of TLS1.3 0-RTT Christian Huitema
- Re: [TLS] Security review of TLS1.3 0-RTT Kyle Nekritz
- Re: [TLS] Security review of TLS1.3 0-RTT Colm MacCárthaigh
- Re: [TLS] Security review of TLS1.3 0-RTT Christian Huitema
- Re: [TLS] Security review of TLS1.3 0-RTT Colm MacCárthaigh
- Re: [TLS] Security review of TLS1.3 0-RTT Benjamin Kaduk
- Re: [TLS] Security review of TLS1.3 0-RTT Colm MacCárthaigh
- Re: [TLS] Security review of TLS1.3 0-RTT Christian Huitema
- Re: [TLS] Security review of TLS1.3 0-RTT Viktor Dukhovni
- Re: [TLS] Security review of TLS1.3 0-RTT Colm MacCárthaigh
- Re: [TLS] Security review of TLS1.3 0-RTT Viktor Dukhovni
- Re: [TLS] Security review of TLS1.3 0-RTT Colm MacCárthaigh
- Re: [TLS] Security review of TLS1.3 0-RTT Benjamin Kaduk
- Re: [TLS] Security review of TLS1.3 0-RTT Salz, Rich
- Re: [TLS] Security review of TLS1.3 0-RTT Salz, Rich
- Re: [TLS] Security review of TLS1.3 0-RTT Benjamin Kaduk
- Re: [TLS] Security review of TLS1.3 0-RTT Benjamin Kaduk
- Re: [TLS] Security review of TLS1.3 0-RTT Ilari Liusvaara
- Re: [TLS] Security review of TLS1.3 0-RTT Colm MacCárthaigh
- Re: [TLS] Security review of TLS1.3 0-RTT Benjamin Kaduk
- Re: [TLS] Security review of TLS1.3 0-RTT Victor Vasiliev
- Re: [TLS] Security review of TLS1.3 0-RTT Dave Garrett
- Re: [TLS] Security review of TLS1.3 0-RTT Colm MacCárthaigh
- Re: [TLS] Security review of TLS1.3 0-RTT Ilari Liusvaara
- Re: [TLS] Security review of TLS1.3 0-RTT Victor Vasiliev
- Re: [TLS] Security review of TLS1.3 0-RTT Colm MacCárthaigh
- Re: [TLS] Security review of TLS1.3 0-RTT Bill Cox
- Re: [TLS] Security review of TLS1.3 0-RTT Ilari Liusvaara
- Re: [TLS] Security review of TLS1.3 0-RTT Victor Vasiliev
- Re: [TLS] Security review of TLS1.3 0-RTT Colm MacCárthaigh
- Re: [TLS] Security review of TLS1.3 0-RTT Eric Rescorla
- Re: [TLS] Security review of TLS1.3 0-RTT Colm MacCárthaigh
- Re: [TLS] Security review of TLS1.3 0-RTT Ilari Liusvaara
- Re: [TLS] Security review of TLS1.3 0-RTT Eric Rescorla
- Re: [TLS] Security review of TLS1.3 0-RTT Eric Rescorla
- Re: [TLS] Security review of TLS1.3 0-RTT Victor Vasiliev
- Re: [TLS] Security review of TLS1.3 0-RTT Victor Vasiliev
- Re: [TLS] Security review of TLS1.3 0-RTT Ilari Liusvaara
- Re: [TLS] Security review of TLS1.3 0-RTT Bill Cox
- Re: [TLS] Security review of TLS1.3 0-RTT Colm MacCárthaigh
- Re: [TLS] Security review of TLS1.3 0-RTT Benjamin Kaduk
- Re: [TLS] Security review of TLS1.3 0-RTT Benjamin Kaduk
- Re: [TLS] Security review of TLS1.3 0-RTT Benjamin Kaduk
- Re: [TLS] Security review of TLS1.3 0-RTT Bill Cox
- Re: [TLS] Security review of TLS1.3 0-RTT Yoav Nir