1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
|
Received: from sog-mx-4.v43.ch3.sourceforge.com ([172.29.43.194]
helo=mx.sourceforge.net)
by sfs-ml-2.v29.ch3.sourceforge.com with esmtp (Exim 4.76)
(envelope-from <jgarzik@bitpay.com>) id 1XJQat-0001df-LF
for bitcoin-development@lists.sourceforge.net;
Mon, 18 Aug 2014 17:19:43 +0000
Received-SPF: pass (sog-mx-4.v43.ch3.sourceforge.com: domain of bitpay.com
designates 209.85.213.49 as permitted sender)
client-ip=209.85.213.49; envelope-from=jgarzik@bitpay.com;
helo=mail-yh0-f49.google.com;
Received: from mail-yh0-f49.google.com ([209.85.213.49])
by sog-mx-4.v43.ch3.sourceforge.com with esmtps (TLSv1:RC4-SHA:128)
(Exim 4.76) id 1XJQas-0007DR-HV
for bitcoin-development@lists.sourceforge.net;
Mon, 18 Aug 2014 17:19:43 +0000
Received: by mail-yh0-f49.google.com with SMTP id b6so4739273yha.36
for <bitcoin-development@lists.sourceforge.net>;
Mon, 18 Aug 2014 10:19:36 -0700 (PDT)
X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed;
d=1e100.net; s=20130820;
h=x-gm-message-state:mime-version:in-reply-to:references:from:date
:message-id:subject:to:cc:content-type;
bh=FXDv2MB+Iek8Vj7wA7OlKXVdyY+6PuPRjW/pMUJ1Lso=;
b=lzit7LDGOQOTdNfdFybgv1EicQY7zBMDkIbmYDrC+XxFVGIjv/ws2zdseHORc3n0DW
JOs1gEtouSygQcz/WylKktU6GnNnR1YAX94+MAbiB+9RMZMnUUAeQB014zwa0G+gCGP7
GN4n2SzQJ99YsINs5pnaZeOV8jW4K7Z43n+dSnba6XoRj8WB+NFKcjTHEZeocYTlZaOi
b7TI9C8DERMjXs2uwr3y9IzMUfEt1tgB1NFb5M8CbSFupz0tqKpZvBDFkXq/44cOTae4
cj8Ekq3c+M8m0evpa6Edj8+O3SAkv1E7Xlf2lxvSafKmaJKdDGGgYVy5B2iJLaw+BrK9
a1YQ==
X-Gm-Message-State: ALoCoQlzK05ag+XFOsU6BeN01LN8h6Rld472It+qRkPOxNbrer6K1olz+2atfIONHrDZ7FCB4EPR
X-Received: by 10.236.15.6 with SMTP id e6mr55676097yhe.43.1408382375932; Mon,
18 Aug 2014 10:19:35 -0700 (PDT)
MIME-Version: 1.0
Received: by 10.170.37.200 with HTTP; Mon, 18 Aug 2014 10:19:15 -0700 (PDT)
In-Reply-To: <20140818164543.GB31175@localhost.localdomain>
References: <20140818164543.GB31175@localhost.localdomain>
From: Jeff Garzik <jgarzik@bitpay.com>
Date: Mon, 18 Aug 2014 13:19:15 -0400
Message-ID: <CAJHLa0PvDz5iEad0w7TvM9O3FSjxRu-noRG-KpC7L-ix6Z0i=A@mail.gmail.com>
To: Ivan Pustogarov <ivan.pustogarov@uni.lu>
Content-Type: text/plain; charset=UTF-8
X-Spam-Score: -1.6 (-)
X-Spam-Report: Spam Filtering performed by mx.sourceforge.net.
See http://spamassassin.org/tag/ for more details.
-1.5 SPF_CHECK_PASS SPF reports sender host as permitted sender for
sender-domain
-0.0 SPF_PASS SPF: sender matches SPF record
-0.1 DKIM_VALID_AU Message has a valid DKIM or DK signature from
author's domain
0.1 DKIM_SIGNED Message has a DKIM or DK signature,
not necessarily valid
-0.1 DKIM_VALID Message has at least one valid DKIM or DK signature
X-Headers-End: 1XJQas-0007DR-HV
Cc: Bitcoin Dev <bitcoin-development@lists.sourceforge.net>
Subject: Re: [Bitcoin-development] Outbound connections rotation
X-BeenThere: bitcoin-development@lists.sourceforge.net
X-Mailman-Version: 2.1.9
Precedence: list
List-Id: <bitcoin-development.lists.sourceforge.net>
List-Unsubscribe: <https://lists.sourceforge.net/lists/listinfo/bitcoin-development>,
<mailto:bitcoin-development-request@lists.sourceforge.net?subject=unsubscribe>
List-Archive: <http://sourceforge.net/mailarchive/forum.php?forum_name=bitcoin-development>
List-Post: <mailto:bitcoin-development@lists.sourceforge.net>
List-Help: <mailto:bitcoin-development-request@lists.sourceforge.net?subject=help>
List-Subscribe: <https://lists.sourceforge.net/lists/listinfo/bitcoin-development>,
<mailto:bitcoin-development-request@lists.sourceforge.net?subject=subscribe>
X-List-Received-Date: Mon, 18 Aug 2014 17:19:43 -0000
Simply by observing timing from sufficiently geo-graphically and
network-ly dispersed nodes, you may deduce the original broadcaster of
a transaction. Rotating peers doesn't help.
That said, periodic rotation can be helpful. Every 2-10 minutes is excessive.
On Mon, Aug 18, 2014 at 12:46 PM, Ivan Pustogarov
<ivan.pustogarov@uni.lu> wrote:
> Hi there,
>
> I'd like to start a discussion on periodic rotation of outbound connections.
> E.g. every 2-10 minutes an outbound connections is dropped and replaced
> by a new one.
>
> Motivation:
> Each bitcoin non-UPnP client behind NAT has 8 outbound connections
> which change only rarely (due to occasional remote side disconnections).
> A subset of these 8 entry nodes uniquely identifies a user.
> An attacker can listen for transactions in Bitcoin network and for each
> transaction record the first 8 peers which forwarded the transaction.
> If two distinct transactions (with unrelated bitcoin addresses)
> come from the same set of 8 peers, the attacker can conclude that they
> originated from the same user. This gives another method (in addition
> to transaction graph analysis) for an attacker to link different BC
> addresses of the same user.
> Also note that by default bitcoin clients advertise their public IP
> addresses. The attacker can link the advertised IP's to corresponding
> 8 entry nodes and use it to deanonymise Bitcoin clients.
>
> If a bitcoin client periodically rotates his set of outbound
> connections, his 8-peers fingerprint is blurred over time.
>
> Corresponding pull request is #4723.
>
> Some details are here: https://www.cryptolux.org/index.php/Bitcoin
>
> --
> Ivan
>
> ------------------------------------------------------------------------------
> _______________________________________________
> Bitcoin-development mailing list
> Bitcoin-development@lists.sourceforge.net
> https://lists.sourceforge.net/lists/listinfo/bitcoin-development
--
Jeff Garzik
Bitcoin core developer and open source evangelist
BitPay, Inc. https://bitpay.com/
|
