Re: [TLS] A closer look at ROBOT, BB Attacks, timing attacks in general, and what we can do in TLS

Ilari Liusvaara <ilariliusvaara@welho.com> Fri, 15 December 2017 18:49 UTC

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Date: Fri, 15 Dec 2017 20:49:51 +0200
From: Ilari Liusvaara <ilariliusvaara@welho.com>
To: Andrei Popov <Andrei.Popov@microsoft.com>
Cc: Eric Rescorla <ekr@rtfm.com>, "tls@ietf.org" <tls@ietf.org>
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Subject: Re: [TLS] A closer look at ROBOT, BB Attacks, timing attacks in general, and what we can do in TLS
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On Fri, Dec 15, 2017 at 06:41:06PM +0000, Andrei Popov wrote:
> It's true, the migration will be slow, but IMHO it still makes sense
> to define and implement an alternative hash.

Agreed. However, on certificates front, we need a method to perform
backward-compatible algorithm transition. Because non-backward-
compatible ones are just too hard. As we have seen _twice_.

On TLS handshake hashes, the transitions are already backward-
compatible. But that does not mean the transition will be easy.




-Ilari