From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from sog-mx-4.v43.ch3.sourceforge.com ([172.29.43.194] helo=mx.sourceforge.net) by sfs-ml-1.v29.ch3.sourceforge.com with esmtp (Exim 4.76) (envelope-from ) id 1Qp6DG-0000v0-Rf for bitcoin-development@lists.sourceforge.net; Thu, 04 Aug 2011 22:16:22 +0000 Received-SPF: pass (sog-mx-4.v43.ch3.sourceforge.com: domain of bluematt.me designates 173.246.101.161 as permitted sender) client-ip=173.246.101.161; envelope-from=bitcoin-list@bluematt.me; helo=mail.bluematt.me; Received: from vps.bluematt.me ([173.246.101.161] helo=mail.bluematt.me) by sog-mx-4.v43.ch3.sourceforge.com with esmtp (Exim 4.76) id 1Qp6DF-0002YG-Qe for bitcoin-development@lists.sourceforge.net; Thu, 04 Aug 2011 22:16:22 +0000 Received: from [IPv6:2001:470:9ff2:1:2c0:caff:fe33:858b] (unknown [IPv6:2001:470:9ff2:1:2c0:caff:fe33:858b]) by mail.bluematt.me (Postfix) with ESMTPSA id 3F8A62CCD for ; Fri, 5 Aug 2011 00:16:09 +0200 (CEST) From: Matt Corallo To: bitcoin-development@lists.sourceforge.net In-Reply-To: References: <201108041423.14176.andyparkins@gmail.com> <201108041922.16956.andyparkins@gmail.com> <1312483196.3109.38.camel@Desktop666> <201108042042.55214.andyparkins@gmail.com> Content-Type: multipart/signed; micalg="pgp-sha1"; protocol="application/pgp-signature"; boundary="=-koQb+HMDBR5uLSn7qVCJ" Date: Fri, 05 Aug 2011 00:16:13 +0200 Message-ID: <1312496173.3109.55.camel@Desktop666> Mime-Version: 1.0 X-Mailer: Evolution 2.32.2 X-Spam-Score: -2.3 (--) 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 -0.8 RP_MATCHES_RCVD Envelope sender domain matches handover relay domain X-Headers-End: 1Qp6DF-0002YG-Qe Subject: Re: [Bitcoin-development] Double spend detection to speed up transaction trust X-BeenThere: bitcoin-development@lists.sourceforge.net X-Mailman-Version: 2.1.9 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Thu, 04 Aug 2011 22:16:22 -0000 --=-koQb+HMDBR5uLSn7qVCJ Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable On Thu, 2011-08-04 at 23:36 +0200, Mike Hearn wrote: > The vending machine/detecting double spends issue was discussed by > Satoshi in July 2010: >=20 > https://bitcointalk.org/index.php?topic=3D423.msg3819#msg3819 >=20 > He mentioned payment processors that could "alert the transaction is bad"= . I stand with satoshi here. No need to add more stuff to the network protocol, a well-connected node can easily monitor the miners(/network) for double-spends and alert whoever may need to know that the transaction should not be accepted. True, not everyone has the resources to try to implement this, however the number of people who have the resources to implement a Bitcoin storefront and not implement this (vs those who will/do use a payment processor who handles such things), I would think, are fairly small. Additionally, keep in mind that many storefronts don't need to care if a transaction confirms in 10 seconds or 1 hour. Only digital goods and physical purchases could benefit from such speed increases. On Fri, 2011-08-05 at 00:10 +0200, Stefan Thomas wrote: Since nobody else has mentioned it: There is another (more pragmatic?)=20 > way to detect double spends: >=20 > 1. Connect to lots of clients > 2a. If they all send you the same transaction -> double spend unlikely > 2b. If some don't send you the transaction (or send a conflicting one)= =20 > -> double spend in progress This is exactly what I've been suggesting this whole time. --=-koQb+HMDBR5uLSn7qVCJ Content-Type: application/pgp-signature; name="signature.asc" Content-Description: This is a digitally signed message part -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.11 (GNU/Linux) iQIcBAABAgAGBQJOOxorAAoJEBrh01BD4I5UpjUQAIvIeoHcYoqReb/H634AmxcO 3qrKdY+Ro496TdRAj2q2SWN4z99tovSY9CFe5hWFWzLndoNcR+1c4e+75rNwtuoX cmsyT/ruyRX19BDMAj0K+HYGoczQtjj4A2UviSC/QbjibG2elFOVzddfRpz5evFp pXFFnYHA/PxNcjN/EpHklfSDOvh+ElGxKwFozjnJypKQ+/15Yy4+Oy+tSkcab9ye 9bHvhhONegum1MMqEwXjexS0omwO3ops14PMai3Ytwyp14VEE5uHpqvPBQvCG4Jr /c46eQDOd2UEMnzUXBzfPFwURYvp4b1YvTRA8dQYFIcMyzSdh4SmbK2LfEk+i/0r PvUNGoVUuR5iBlVRhEDi03aZRBORZ4Bms5y1Rc7t1B2R5n6nLnDTcH1Z73WyjSci fEWKuU0/ul8Pw+hMvo3S9+QdZIOVV8Cn9u9ZRi8pPqwH3i9rXgjm0Pky0c6I8Rdn HZXP1U5FIj+021MF8qKEFpvKk0911UUiCTmUMRdvAfjrH/Qod3P4AVqHzvS32j42 YeWK8PZRA9ez3+pBsrBNB7xC3FaXcDZwTbxspNPi5pgqGjgZG9wgxHI4IQeyYxUF L5xYZa1/qQzAmBvmfzBOgvTSLGt0V2Uq3bs6JqcpE9M9crmKLDM02qeggVzhOwcO T+CvNGj4OAA58sXtw+hP =H1YO -----END PGP SIGNATURE----- --=-koQb+HMDBR5uLSn7qVCJ--