From mboxrd@z Thu Jan 1 00:00:00 1970 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 ) id 1Z25X0-0007us-9h for bitcoin-development@lists.sourceforge.net; Mon, 08 Jun 2015 22:28:34 +0000 Received-SPF: pass (sog-mx-2.v43.ch3.sourceforge.com: domain of petertodd.org designates 62.13.148.100 as permitted sender) client-ip=62.13.148.100; envelope-from=pete@petertodd.org; helo=outmail148100.authsmtp.co.uk; Received: from outmail148100.authsmtp.co.uk ([62.13.148.100]) by sog-mx-2.v43.ch3.sourceforge.com with esmtp (Exim 4.76) id 1Z25Wy-0004VS-VK for bitcoin-development@lists.sourceforge.net; Mon, 08 Jun 2015 22:28:34 +0000 Received: from mail-c235.authsmtp.com (mail-c235.authsmtp.com [62.13.128.235]) by punt15.authsmtp.com (8.14.2/8.14.2/) with ESMTP id t58MSPLh073608; Mon, 8 Jun 2015 23:28:25 +0100 (BST) Received: from muck (bas3-cooksville17-1176329630.dsl.bell.ca [70.29.93.158]) (authenticated bits=128) by mail.authsmtp.com (8.14.2/8.14.2/) with ESMTP id t58MSHsB036331 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES128-SHA bits=128 verify=NO); Mon, 8 Jun 2015 23:28:23 +0100 (BST) Date: Mon, 8 Jun 2015 18:28:16 -0400 From: Peter Todd To: Bob McElrath Message-ID: <20150608222815.GB10819@muck> References: <5574E39C.3090904@thinlink.com> <7E7DF414-6DDB-48A6-9199-D6883209B67D@newcastle.ac.uk> <20150608214443.GC19826@muck> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha256; protocol="application/pgp-signature"; boundary="/NkBOFFp2J2Af1nK" Content-Disposition: inline In-Reply-To: X-Server-Quench: ad13a142-0e2d-11e5-b396-002590a15da7 X-AuthReport-Spam: If SPAM / abuse - report it at: http://www.authsmtp.com/abuse X-AuthRoute: OCd2Yg0TA1ZNQRgX IjsJECJaVQIpKltL GxAVKBZePFsRUQkR bgdMdgoUEkAaAgsB AmMbWVdeUlV7W2c7 bApPbwxDa0lQXgBi T01BRU1TWkFtCWFi fl1sUhp0dAZHNn9z bU9nECEPXUcrdEJ/ X04BFzkbZGY1bX1N U0leagNUcgZDfk5E bwQuUz1vNG8XDQg5 AwQ0PjZ0MThBJSBS WgQAK04nCWAGAXY1 WwwLFjZnHEEIQTky IR0rJhYVGkpZKkIu PF09WFscUVcJDQlD A0BKBk5VKkIKXSsh AA8IFWIEFyVFTCsZ HgchJARBCSBTXSwQ H1NMTlkGFz9MWyoA QTlUUys2EBA1J09i OCAYOgJTegY/WRcF CRwXR1cw X-Authentic-SMTP: 61633532353630.1023:706 X-AuthFastPath: 0 (Was 255) X-AuthSMTP-Origin: 70.29.93.158/587 X-AuthVirus-Status: No virus detected - but ensure you scan with your own anti-virus system. X-Spam-Score: -1.5 (-) 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 X-Headers-End: 1Z25Wy-0004VS-VK Cc: "Patrick Mccorry \(PGR\)" , Bitcoin Dev Subject: Re: [Bitcoin-development] New attack identified and potential solution described: Dropped-transaction spam attack against the block size limit 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: Mon, 08 Jun 2015 22:28:34 -0000 --/NkBOFFp2J2Af1nK Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Mon, Jun 08, 2015 at 06:06:00PM -0400, Bob McElrath wrote: > There was this wonderful technology invented a few years ago to deal with= spam. It's called Hashcash. All these hacky heuristics like block size are= just dancing around the problem, and the natural solution is already prese= nt in bitcoin: smaller blocks, (down to the point of individual transaction= s) each mined. Don't relay things that haven't been mined. As spam or trans= action levels go up, mining targets for submission go up too. You know, you can think of Bitcoin as a system that maintains a ledger for transferrable hashcash... Which means transaction fees *are* paid in hashcash. --=20 'peter'[:-1]@petertodd.org 0000000000000000127ab1d576dc851f374424f1269c4700ccaba2c42d97e778 --/NkBOFFp2J2Af1nK Content-Type: application/pgp-signature; name="signature.asc" Content-Description: Digital signature -----BEGIN PGP SIGNATURE----- iQGrBAEBCACVBQJVdhb9XhSAAAAAABUAQGJsb2NraGFzaEBiaXRjb2luLm9yZzAw MDAwMDAwMDAwMDAwMDAxMjdhYjFkNTc2ZGM4NTFmMzc0NDI0ZjEyNjljNDcwMGNj YWJhMmM0MmQ5N2U3NzgvFIAAAAAAFQARcGthLWFkZHJlc3NAZ251cGcub3JncGV0 ZUBwZXRlcnRvZC5vcmcACgkQwIXyHOf0udwOgAf+IaJoA4iPpmSeYZWnmubMgvST Er/lERCZPuuJ6jXEj1y/Qav/tgvKjreXKBk3lBpFmHFjmt3nk9tV4TkZMWGtq2oz qWJJRwfJRq8oc6fGRHAU8iv/jDOsptxqHEFS5AdxBMu+OjV4Fdd/3uiWBxWVZWLd s2HHktuFbhmuyD3YdifTgxpzrtBDBvbQ1GaxwRWX+W6H2RJx1cxOOZiBeh6BVNQi 8Dq++YeUaGZ5K3ylDfh9wAjQwgtorXouCjimrYKbPEO12/rhwAyt49KsJg8FiWIb NfQNaK5O4TUVnubJWV9Yr3DQJyfuF2/toE21Gg3gs/I7hBn4Dhx6DCj4bl5z4A== =TXGn -----END PGP SIGNATURE----- --/NkBOFFp2J2Af1nK--