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Re: [perpass] DNS confidentiality

"Christian Huitema" <huitema@huitema.net> Sun, 29 September 2013 06:36 UTC

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From: Christian Huitema <huitema@huitema.net>
To: 'Hosnieh Rafiee' <ietf@rozanak.com>, 'Stephen Farrell' <stephen.farrell@cs.tcd.ie>
References: <524150C7.2020602@cs.tcd.ie> <1380054665.62304.YahooMailNeo@web125505.mail.ne1.yahoo.com> <006a01ceb96a$335c1df0$9a1459d0$@rozanak.com> <1380137874.48631.YahooMailNeo@web125502.mail.ne1.yahoo.com> <005901ceba2a$f854c1a0$e8fe44e0$@rozanak.com> <1380218914.85280.YahooMailNeo@web125502.mail.ne1.yahoo.com> <003901cebba5$b2762c10$17628430$@rozanak.com> <1380307285.91976.YahooMailNeo@web125501.mail.ne1.yahoo.com> <001b01cebbb6$d5565550$8002fff0$@rozanak.com> <C25E0D41-CDCB-4E53-8661-53E5F0E2B47E@isi.edu> <1380382072.12590.YahooMailNeo@web125504.mail.ne1.yahoo.com> <5246F653.2040300@cs.tcd.ie> <002101cebc62$dda15dc0$98e41940$@rozanak.com>
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Date: Sat, 28 Sep 2013 23:32:58 -0700
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Cc: 'perpass' <perpass@ietf.org>
Subject: Re: [perpass] DNS confidentiality
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Hosnieh,

CGA only protect against MITM attacks if the addresses are exchanged
securely. Otherwise, you get the following situation:

* A wants to connect with B;
* The evil E convinces A that the address of B is  X, a CGA address composed
by E;
* Using CGA, A establishes a secure channel to X;
* Using CGA, E establishes a secure channel  from X to B;

Voila, the connections are properly secured with CGA, yet E is in the
middle.

-- Christian Huitema

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