Re: [hybi] "fresh" and "uniformly at random":

Adam Barth <ietf@adambarth.com> Mon, 20 June 2011 02:57 UTC

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From: Adam Barth <ietf@adambarth.com>
Date: Sun, 19 Jun 2011 19:57:11 -0700
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To: Denis Lagno <dilmah@chromium.org>
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Subject: Re: [hybi] "fresh" and "uniformly at random":
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On Sat, Jun 18, 2011 at 12:34 AM, Denis Lagno <dilmah@chromium.org> wrote:
> On Sat, Jun 18, 2011 at 10:27 AM, Adam Barth <ietf@adambarth.com> wrote:
>> The term "fresh" is a term of art in cryptography.  It means, roughly,
>> "not used previously."
>
> So this implies that client must keep track of already used keys? it
> imposes limit on length of connection?
> True it or false, It should be explicitly clarified in the text.

The normal practice in cryptography is to just use large enough values
such that the probably of collision is sufficiently small as to be
acceptable.  For example, if you use a 20 byte nonce, the probably of
collision is zero for all practical purposes.

This stuff is all extremely normal.

Adam