From: Carl Ellison <cme@TIS.COM>
Date: Sun, 29 Oct 1995 22:58:26 +0800
To: hfinney@shell.portal.com
Subject: Re:  Human ID through insecure channel
Message-ID: <9510291444.AA24504@tis.com>
MIME-Version: 1.0
Content-Type: text/plain


>Date: Mon, 16 Oct 1995 13:51:27 -0700
>From: Hal <hfinney@shell.portal.com>
>Subject: Human ID through insecure channel
>
>Here is an example of the Matsumoto/Imai scheme for identifying yourself
>via a shared secret over an insecure channel, a system which is simple
>enough to be done in your head but which can withstand repeated
>observations by an adversary without being broken.


Hal,

	has this been written up someplace where I might read their
description?

	From your description of it, I have a way to break it in O(N)
samples, where N is the number of characters in the challenge string and
the factor of proportionality is strictly a function of how sure you want
to be that you have a correct break.


 - Carl


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