> Switching to a protocol like TLS 1.3 as it is today to fix that thing it is 
> an overkill.

The primary purpose of a security protocol is to support security as best as 
possible. Knowing security gaps causes distrust in general. Probably not in the 
security protocol experts community, but in the overall communications and 
information technology industry.
The quantification of "overkill" should be rated from that trust perspective in 
my opinion.

Albrecht

-----Original Message-----
From: TLS [mailto:tls-boun...@ietf.org] On Behalf Of Nikos Mavrogiannopoulos
Sent: Mittwoch, 13. Januar 2016 10:54
To: Yoav Nir; Peter Gutmann
Cc: <tls@ietf.org>
Subject: Re: [TLS] Fixing TLS

On Tue, 2016-01-12 at 19:13 +0200, Yoav Nir wrote:
> Hi, Peter
> 
> Ignoring for a moment the merits of this proposal vs the TLS 1.3 (or
> 2.0) that this WG is working on right now, why?
> Other groups are not working on HTTP/1.2 or IKEv1.1 or any other 
> $protocolv$(major-1).$(minor+1).

Note that these are not security protocols and they don't benefit from a formal 
analysis of a protocol. Such an analysis takes several years to be done and it 
often applies to small parts of the protocol.
Switching to a new version invalidates all the existing analysis.

That is of course not necessarily bad, but as we are moving towards formally 
verified protocols it is very bad to give these two options:
1. Stay with a formally verified but with known vulnerabilities protocol 2. 
Switch to a new unknown protocol which has not been studied by as many 
cryptographers but is _believed_ to solve the issues found in TLS.


> Any TLS library that exists now doesn’t have an implementation of 
> either “your” TLS 1.3 or “our” TLS 1.3. To get either, you’ll need to 
> get an upgraded version of your favorite library. So the upgrade path 
> is no smoother for either protocol.   If this had been brought up 
> before the work on the current draft started, maybe we would be 
> convinced. As it is, I don’t see the point.

The main problem of TLS 1.2 is that it is vulnerable to cross-protocol attacks 
and there is no way to mitigate that. There was such an attack described in 
2012 and another in 2015 [0]. Whether there will be a new one in 2017 is an 
open question. Switching to a protocol like TLS 1.3 as it is today to fix that 
thing it is an overkill.

That is because TLS 1.3 is a rewrite of the protocol, and requires a rewrite of 
the code base. Given that the majority of the issues in TLS implementations are 
in the code bases and not in the protocol, it is very risky to switch to such a 
new version just like that. For old systems it most likely will never happen 
and they will remain vulnerable.

[0]. https://weakdh.org/imperfect-forward-secrecy-ccs15.pdf

regards,
Nikos


_______________________________________________
TLS mailing list
TLS@ietf.org
https://www.ietf.org/mailman/listinfo/tls
_______________________________________________
TLS mailing list
TLS@ietf.org
https://www.ietf.org/mailman/listinfo/tls

Reply via email to