From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from sog-mx-3.v43.ch3.sourceforge.com ([172.29.43.193] helo=mx.sourceforge.net) by sfs-ml-4.v29.ch3.sourceforge.com with esmtp (Exim 4.76) (envelope-from ) id 1UcZk0-0007fw-AP for bitcoin-development@lists.sourceforge.net; Wed, 15 May 2013 11:19:28 +0000 Received-SPF: pass (sog-mx-3.v43.ch3.sourceforge.com: domain of petertodd.org designates 62.13.149.113 as permitted sender) client-ip=62.13.149.113; envelope-from=pete@petertodd.org; helo=outmail149113.authsmtp.com; Received: from outmail149113.authsmtp.com ([62.13.149.113]) by sog-mx-3.v43.ch3.sourceforge.com with esmtp (Exim 4.76) id 1UcZjz-0000nc-8q for bitcoin-development@lists.sourceforge.net; Wed, 15 May 2013 11:19:28 +0000 Received: from mail-c232.authsmtp.com (mail-c232.authsmtp.com [62.13.128.232]) by punt5.authsmtp.com (8.14.2/8.14.2/Kp) with ESMTP id r4FBJGsP017227; Wed, 15 May 2013 12:19:16 +0100 (BST) Received: from savin (76-10-178-109.dsl.teksavvy.com [76.10.178.109]) (authenticated bits=128) by mail.authsmtp.com (8.14.2/8.14.2/) with ESMTP id r4FBJ7DH068637 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES128-SHA bits=128 verify=NO); Wed, 15 May 2013 12:19:09 +0100 (BST) Date: Wed, 15 May 2013 07:19:06 -0400 From: Peter Todd To: Adam Back Message-ID: <20130515111906.GA26020@savin> References: <20130514115151.GA21600@netbook.cypherspace.org> <20130514140902.GA22447@netbook.cypherspace.org> <20130515102509.GA3401@netbook.cypherspace.org> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha256; protocol="application/pgp-signature"; boundary="M9NhX3UHpAaciwkO" Content-Disposition: inline In-Reply-To: <20130515102509.GA3401@netbook.cypherspace.org> User-Agent: Mutt/1.5.21 (2010-09-15) X-Server-Quench: 43ff12ca-bd51-11e2-b10b-0025903375e2 X-AuthReport-Spam: If SPAM / abuse - report it at: http://www.authsmtp.com/abuse X-AuthRoute: OCd2Yg0TA1ZNQRgX IjsJECJaVQIpKltL GxAVKBZePFsRUQkR aAdMdwcUFVQNAgsB AmUbWlZeUVR7WGM7 bAxPbAVDY01GQQRq WVdMSlVNFUsqBWpz fBlqKhl0fwNFfzB4 bU5hEHRYChJ7dxUs XxwAEGwbZGY1an1N UUAKagNUcgZDfhxG bVUqVj1vNG8XDQg5 AwQ0PjZ0MThBJSBS WgQAK04nCUwPHzgw DwsTGDAiAVcETG04 KBkjK0IZEUANeks1 KxM6RUgfNRAfEG8W FVBfCSlFJl8MDzQs EQJcUgYEHSZcRSZR BBYlal9yD24aUCtE D0xETVkTAiJDTGEG ACtbUykkEFUzLkZi KCkBNgo4ERw6SgZc THUA X-Authentic-SMTP: 61633532353630.1019:706 X-AuthFastPath: 0 (Was 255) X-AuthSMTP-Origin: 76.10.178.109/587 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: 1UcZjz-0000nc-8q Cc: Bitcoin-Dev Subject: Re: [Bitcoin-development] blind symmetric commitment for stronger byzantine voting resilience (Re: bitcoin taint & unilateral revocability) 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: Wed, 15 May 2013 11:19:28 -0000 --M9NhX3UHpAaciwkO Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Wed, May 15, 2013 at 12:25:09PM +0200, Adam Back wrote: Protocols aren't set in stone - any attacker that controls enough hashing power to pose a 51% attack can simply demand that you use a Bitcoin client modified to provide the attack with the full transactions =66rom the beginning. Any blocks containing transactions with unknown contents will be attacked into oblivion. On the other hand if the "attacker" has less than 50% of the hashing power, they have no choice but to let other blocks through, and provided miners are free from regulation imposed on them you can bid to get your transactions mined with fees. Anyone using a blockchain-based crypto-currency simply has to accept that mining is a random process and getting a transaction confirmed is inherently unreliable. > So in a previous mail I described a simple, extremely efficient and easy = to > implement symmetric key commitment that is unlinkable until reveal time (= at > bottom). I think this can help improve the byzantine generals problem, t= hat > bitcoin only defends to simple majority (with one vote per CPU power), and > so assumes most nodes by cpu power are honest. With this simple protocol > change you dont need any honest nodes, just some honest clients to spend = to, > to have your transaction accepted. =20 --=20 'peter'[:-1]@petertodd.org 00000000000001754b62829d854463fa72fe7d972a7b7d13d0c30fc86423773c --M9NhX3UHpAaciwkO Content-Type: application/pgp-signature; name="signature.asc" Content-Description: Digital signature -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.11 (GNU/Linux) iQEcBAEBCAAGBQJRk28qAAoJECSBQD2l8JH7li0IAK4q+LW9mi8Rk7lwpTYygxmD ltWAlZLPtZbw883MvZfkTLqk/rKU2b00kN2WCohHjoPEd8DfKe+B7yvliPK5UvW6 KZDHnHyHXD9gA36yjFyrwL3C2MehmvUaKqhCIwNZcjzb49OK4si+rIZC/8FqyWp7 DLYKIhe5gPd6Y6wQhAM0fFiaHEC5RBNMBlBsCmeWa/fBIkuQSfTgwOIwmLVD2G5T XHbnDwRFP2bZHWcZ5O1IFj8H4veOaHqXC9OjWvkqVJCSZlKfKTqvQrA+Aaa/RoBN v7YKLBlt2MrEcJ4hD2ZxasReqXl7ZUX1mRDWIBF6k2+L/rYKTgztcmyPlLbOpFk= =/Y16 -----END PGP SIGNATURE----- --M9NhX3UHpAaciwkO--