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
|
Received: from sog-mx-3.v43.ch3.sourceforge.com ([172.29.43.193]
helo=mx.sourceforge.net)
by sfs-ml-2.v29.ch3.sourceforge.com with esmtp (Exim 4.76)
(envelope-from <andyparkins@gmail.com>) id 1Wcx7m-0003vP-7q
for bitcoin-development@lists.sourceforge.net;
Wed, 23 Apr 2014 13:22:06 +0000
Received-SPF: pass (sog-mx-3.v43.ch3.sourceforge.com: domain of gmail.com
designates 74.125.82.47 as permitted sender)
client-ip=74.125.82.47; envelope-from=andyparkins@gmail.com;
helo=mail-wg0-f47.google.com;
Received: from mail-wg0-f47.google.com ([74.125.82.47])
by sog-mx-3.v43.ch3.sourceforge.com with esmtps (TLSv1:RC4-SHA:128)
(Exim 4.76) id 1Wcx7k-00038w-8M
for bitcoin-development@lists.sourceforge.net;
Wed, 23 Apr 2014 13:22:06 +0000
Received: by mail-wg0-f47.google.com with SMTP id x12so835136wgg.18
for <bitcoin-development@lists.sourceforge.net>;
Wed, 23 Apr 2014 06:21:58 -0700 (PDT)
X-Received: by 10.195.13.76 with SMTP id ew12mr529830wjd.80.1398259318102;
Wed, 23 Apr 2014 06:21:58 -0700 (PDT)
Received: from grissom.localnet ([91.84.15.31])
by mx.google.com with ESMTPSA id q2sm29013104wix.5.2014.04.23.06.21.56
for <multiple recipients>
(version=TLSv1 cipher=ECDHE-RSA-RC4-SHA bits=128/128);
Wed, 23 Apr 2014 06:21:57 -0700 (PDT)
From: Andy Parkins <andyparkins@gmail.com>
To: Mike Hearn <mike@plan99.net>
Date: Wed, 23 Apr 2014 14:21:53 +0100
User-Agent: KMail/1.13.7 (Linux/3.2.0-1-686-pae; KDE/4.8.4; i686; ; )
References: <CANEZrP0szimdFSk23aMfO8p2Xtgfbm6kZ=x3rmdPDFUD73xHMg@mail.gmail.com>
<201404231239.20202.andyparkins@gmail.com>
<CANEZrP3w0XY_2bUG-+L57gMU2psicWu5dUv3O1S7hgaq_+8Xqg@mail.gmail.com>
In-Reply-To: <CANEZrP3w0XY_2bUG-+L57gMU2psicWu5dUv3O1S7hgaq_+8Xqg@mail.gmail.com>
MIME-Version: 1.0
Content-Type: Text/Plain;
charset="iso-8859-15"
Content-Transfer-Encoding: 7bit
Message-Id: <201404231421.53349.andyparkins@gmail.com>
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 FREEMAIL_FROM Sender email is commonly abused enduser mail provider
(andyparkins[at]gmail.com)
-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: 1Wcx7k-00038w-8M
Cc: Bitcoin Dev <bitcoin-development@lists.sourceforge.net>
Subject: Re: [Bitcoin-development] Coinbase reallocation to discourage
Finney attacks
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: Wed, 23 Apr 2014 13:22:06 -0000
On Wednesday 23 Apr 2014 12:45:34 Mike Hearn wrote:
> OK, sure, let's say most Bitcoin users will be honest (we hope). But
> unfortunately in a situation where fraud is possible users wouldn't
> necessarily distribute evenly over transactions.
That's true, but even in the worst that that 5% hashing power attack means
that 95% of the time, your attack fails. That means you end up paying for
what you bought. Also, you're again changing the comparison basis -- your
CC figures were for the entire industry, not the most badly affected
merchant. You can't say "one particular bitcoin merchant suffers 5% fraud,
therefore that's worse than the 2% fraud averaged across all CC merchants".
> If a merchant is selling something of value repeatedly, then a small
> number of scammers can go back and try their luck over and over. I'm not
> sure how many trades fall into such an exploitable category, though.
>
> Also, there's the philosophical question of how honest people really are
> when there's no consequences to their actions. For instance, if most
There _are_ consequences though: 95% of the time, you end up buying
something and paying for it.
Viewed another way, if I buy something repeatedly from an at risk merchant
(and there won't be many; as you pointed out, mail order is completely
unaffected as you can simply wait for your confirmations) that costs, say
0.01 BTC per item, then I have to buy 100 of them to get 5 of them for free.
Do I really want 100 of them? Even if I do want them, then I've had to
supply capital of 1 BTC to earn 0.05 BTC in kind.
If what I'm buying is another form of money (as with exchanges, or perhaps
casinos) when that "in kind" is just as liquid as the BTC, then fair enough,
there is a risk, but that just incentivises the merchant in those cases to
not allow withdrawal/deposit until 6 confirmations have been received.
Those merchants then move from "at risk" to "not at risk".
I'm still struggling to see how bitcoin could ever be as bad as CC fraud.
Andy
--
Dr Andy Parkins
andyparkins@gmail.com
|
