Received: from sog-mx-2.v43.ch3.sourceforge.com ([172.29.43.192]
	helo=mx.sourceforge.net)
	by sfs-ml-3.v29.ch3.sourceforge.com with esmtp (Exim 4.76)
	(envelope-from <andyparkins@gmail.com>) id 1WctwL-0004ud-Bq
	for bitcoin-development@lists.sourceforge.net;
	Wed, 23 Apr 2014 09:58:05 +0000
Received-SPF: pass (sog-mx-2.v43.ch3.sourceforge.com: domain of gmail.com
	designates 209.85.212.170 as permitted sender)
	client-ip=209.85.212.170; envelope-from=andyparkins@gmail.com;
	helo=mail-wi0-f170.google.com; 
Received: from mail-wi0-f170.google.com ([209.85.212.170])
	by sog-mx-2.v43.ch3.sourceforge.com with esmtps (TLSv1:RC4-SHA:128)
	(Exim 4.76) id 1WctwK-0005VJ-K7
	for bitcoin-development@lists.sourceforge.net;
	Wed, 23 Apr 2014 09:58:05 +0000
Received: by mail-wi0-f170.google.com with SMTP id bs8so4285596wib.3
	for <bitcoin-development@lists.sourceforge.net>;
	Wed, 23 Apr 2014 02:57:58 -0700 (PDT)
X-Received: by 10.180.104.5 with SMTP id ga5mr985634wib.47.1398247078429;
	Wed, 23 Apr 2014 02:57:58 -0700 (PDT)
Received: from grissom.localnet ([91.84.15.31])
	by mx.google.com with ESMTPSA id vp5sm766400wjc.31.2014.04.23.02.57.57
	for <multiple recipients>
	(version=TLSv1 cipher=ECDHE-RSA-RC4-SHA bits=128/128);
	Wed, 23 Apr 2014 02:57:57 -0700 (PDT)
From: Andy Parkins <andyparkins@gmail.com>
To: bitcoin-development@lists.sourceforge.net
Date: Wed, 23 Apr 2014 10:57:53 +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>
In-Reply-To: <CANEZrP0szimdFSk23aMfO8p2Xtgfbm6kZ=x3rmdPDFUD73xHMg@mail.gmail.com>
MIME-Version: 1.0
Content-Type: Text/Plain;
  charset="iso-8859-15"
Content-Transfer-Encoding: 7bit
Message-Id: <201404231057.54387.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: 1WctwK-0005VJ-K7
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 09:58:05 -0000

On Wednesday 23 Apr 2014 08:55:30 Mike Hearn wrote:

> Even with their woeful security many merchants see <1-2% credit card
> chargeback rates, and chargebacks can be disputed. In fact merchants win
> about 40% of chargeback disputes. So if N was only, say, 5%, and there
> was a large enough population of users who were systematically trying to
> defraud merchants, we'd already be having worse security than magstripe
> credit cards. EMV transactions have loss rates in the noise, so for
> merchants who take those Bitcoin would be dramatically less secure.

Just pedantry: 100% of credit card transactions _can_ be fradulantly charged 
back but arent.  In fact, only 2% are ever attempted.

If N was 5%, then only 5% of bitcoin transactions _could_ be fraudulantly 
"charged back"; so then why wouldn't only 2% of those bitcoin transactions 
be fraudulant too, just as in the CC case?

The comparison would then be 2% chargebacks for credit cards, equivalent to 
0.1% (5%*2%) for bitcoin.


Not that I think that makes anything else you say invalid.



Andy
-- 
Dr Andy Parkins
andyparkins@gmail.com