Delivery-Date: Fri, 29 Aug 2014 20:59:39 -0400
Return-Path: <tor-talk-bounces@lists.torproject.org>
X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on moria.seul.org
X-Spam-Level: 
X-Spam-Status: No, score=-4.7 required=5.0 tests=BAYES_00,DKIM_SIGNED,
	RCVD_IN_DNSWL_MED,RP_MATCHES_RCVD,T_DKIM_INVALID,UNPARSEABLE_RELAY
	autolearn=ham version=3.3.1
X-Original-To: archiver@seul.org
Delivered-To: archiver@seul.org
Received: from eugeni.torproject.org (eugeni.torproject.org [38.229.72.13])
	(using TLSv1.2 with cipher ADH-AES256-GCM-SHA384 (256/256 bits))
	(No client certificate requested)
	by khazad-dum.seul.org (Postfix) with ESMTPS id BC5371E067B;
	Fri, 29 Aug 2014 20:59:37 -0400 (EDT)
Received: from eugeni.torproject.org (localhost [127.0.0.1])
	by eugeni.torproject.org (Postfix) with ESMTP id E893330B25;
	Sat, 30 Aug 2014 00:59:29 +0000 (UTC)
Received: from localhost (localhost [127.0.0.1])
 by eugeni.torproject.org (Postfix) with ESMTP id E588A309D3
 for <tor-talk@lists.torproject.org>; Sat, 30 Aug 2014 00:59:26 +0000 (UTC)
X-Virus-Scanned: Debian amavisd-new at eugeni.torproject.org
Received: from eugeni.torproject.org ([127.0.0.1])
 by localhost (eugeni.torproject.org [127.0.0.1]) (amavisd-new, port 10024)
 with ESMTP id wqlSrMb46kId for <tor-talk@lists.torproject.org>;
 Sat, 30 Aug 2014 00:59:26 +0000 (UTC)
Received: from mx1.riseup.net (mx1.riseup.net [198.252.153.129])
 (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits))
 (Client CN "*.riseup.net", Issuer "Gandi Standard SSL CA" (not verified))
 by eugeni.torproject.org (Postfix) with ESMTPS id C27D9307E8
 for <tor-talk@lists.torproject.org>; Sat, 30 Aug 2014 00:59:26 +0000 (UTC)
Received: from plantcutter.riseup.net (plantcutter-pn.riseup.net [10.0.1.121])
 (using TLSv1 with cipher ECDHE-RSA-AES256-SHA (256/256 bits))
 (Client CN "*.riseup.net", Issuer "Gandi Standard SSL CA" (not verified))
 by mx1.riseup.net (Postfix) with ESMTPS id EE7C2558E0
 for <tor-talk@lists.torproject.org>; Sat, 30 Aug 2014 00:59:23 +0000 (UTC)
DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=riseup.net; s=squak;
 t=1409360364; bh=xX0dpaBYjdQEB9uPAobXgP99XqNn5IMAY6HLeBkaUg4=;
 h=Date:From:To:Subject:References:In-Reply-To:From;
 b=BtinGRSR07SYW30GAu6kOrjlrBcRqvEZtxXcRku8Skd/BFN45N2OHITFKkQMELq/r
 qjKVvzcG6IVg4dGktwcpyzfJPKpeyOH+ULeNt1Obs4fHTvu+agL+uO/D5wDgLI3CZK
 hI4XoL+ipshGiw3wIKV3sxJselhXhCbWEhh2RlCU=
Received: from [127.0.0.1] (localhost [127.0.0.1])
 (Authenticated sender: mirimir) with ESMTPSA id 383B8227C1
Message-ID: <540121E7.2090906@riseup.net>
Date: Fri, 29 Aug 2014 18:59:19 -0600
From: Mirimir <mirimir@riseup.net>
User-Agent: Mozilla/5.0 (X11; Linux x86_64;
 rv:31.0) Gecko/20100101 Thunderbird/31.0
MIME-Version: 1.0
To: tor-talk@lists.torproject.org
References: <20140829112001.40E8A40F7F@mail.unseen.is>
In-Reply-To: <20140829112001.40E8A40F7F@mail.unseen.is>
X-Virus-Scanned: clamav-milter 0.98.4 at mx1
X-Virus-Status: Clean
Subject: Re: [tor-talk] I have a quick question about security of tor with 3
 nodes
X-BeenThere: tor-talk@lists.torproject.org
X-Mailman-Version: 2.1.15
Precedence: list
Reply-To: tor-talk@lists.torproject.org
List-Id: "all discussion about theory, design,
 and development of Onion Routing" <tor-talk.lists.torproject.org>
List-Unsubscribe: <https://lists.torproject.org/cgi-bin/mailman/options/tor-talk>, 
 <mailto:tor-talk-request@lists.torproject.org?subject=unsubscribe>
List-Archive: <http://lists.torproject.org/pipermail/tor-talk/>
List-Post: <mailto:tor-talk@lists.torproject.org>
List-Help: <mailto:tor-talk-request@lists.torproject.org?subject=help>
List-Subscribe: <https://lists.torproject.org/cgi-bin/mailman/listinfo/tor-talk>, 
 <mailto:tor-talk-request@lists.torproject.org?subject=subscribe>
Content-Type: text/plain; charset="us-ascii"
Content-Transfer-Encoding: 7bit
Errors-To: tor-talk-bounces@lists.torproject.org
Sender: "tor-talk" <tor-talk-bounces@lists.torproject.org>

On 08/29/2014 01:55 AM, John Doe wrote:
> Surely this is not as simple as that which you said. Why have even a
> middle node if it is only the first and last nodes that count? I
> cannot believe this is a simple thing of the first and last nodes
> giving people up.

Some do use just entry guard and exit relay, for lower latency.

Even the NSA, with global intercepts, is apparently not doing
full-network traffic correlation among Tor relays. Maybe they will after
Bluffdale is fully functional.

But Sybil attacks are clearly feasible, and require just some cloud
servers and the skills to use them. See Johnson et al. (2013).[0] It
seems that Sybil attacks against Tor are limited in scale not so much by
an adversary's resources, but rather through oversight by Tor Project
staff. Even though Tor is an open network, relays that behave
suspiciously get evicted.

[0] Johnson et al. (2013) Users Get Routed: Traffic Correlation on Tor
by Realistic Adversaries.
http://www.ohmygodel.com/publications/usersrouted-ccs13.pdf
-- 
tor-talk mailing list - tor-talk@lists.torproject.org
To unsubscribe or change other settings go to
https://lists.torproject.org/cgi-bin/mailman/listinfo/tor-talk

