From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from smtp1.linuxfoundation.org (smtp1.linux-foundation.org [172.17.192.35]) by mail.linuxfoundation.org (Postfix) with ESMTPS id 98FC3E0B for ; Fri, 12 Feb 2016 15:35:11 +0000 (UTC) X-Greylist: from auto-whitelisted by SQLgrey-1.7.6 Received: from outmail148154.authsmtp.co.uk (outmail148154.authsmtp.co.uk [62.13.148.154]) by smtp1.linuxfoundation.org (Postfix) with ESMTP id BBAE890 for ; Fri, 12 Feb 2016 15:35:10 +0000 (UTC) Received: from mail-c232.authsmtp.com (mail-c232.authsmtp.com [62.13.128.232]) by punt21.authsmtp.com (8.14.2/8.14.2/) with ESMTP id u1CFZ88B070508; Fri, 12 Feb 2016 15:35:08 GMT Received: from petertodd.org (ec2-52-5-185-120.compute-1.amazonaws.com [52.5.185.120]) (authenticated bits=0) by mail.authsmtp.com (8.14.2/8.14.2/) with ESMTP id u1CFZ25O095534 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=NO); Fri, 12 Feb 2016 15:35:03 GMT Received: from [127.0.0.1] (localhost [127.0.0.1]) by petertodd.org (Postfix) with ESMTPSA id 961C640012; Fri, 12 Feb 2016 15:31:44 +0000 (UTC) Received: by savin (Postfix, from userid 1000) id 07D3913FC08; Fri, 12 Feb 2016 10:35:01 -0500 (EST) Received: by savin (hashcash-sendmail, from uid 1000); Fri, 12 Feb 2016 10:34:53 -0500 Date: Fri, 12 Feb 2016 10:34:53 -0500 From: Peter Todd To: gladoscc Message-ID: <20160212153453.GA4976@savin.petertodd.org> References: MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha256; protocol="application/pgp-signature"; boundary="CE+1k2dSO48ffgeK" Content-Disposition: inline In-Reply-To: X-Hashcash: 1:28:160212:admin+g@glados.cc::xR8ggBS38mhHWnB8:00000000000000000000 000000000000000000000003KR7R X-Hashcash: 1:28:160212:bitcoin-dev@lists.linuxfoundation.org::1cUQl8F64utcb5zj: 0000000000000000000000014xkT X-Server-Quench: 2facbcfb-d19e-11e5-829e-00151795d556 X-AuthReport-Spam: If SPAM / abuse - report it at: http://www.authsmtp.com/abuse X-AuthRoute: OCd2Yg0TA1ZNQRgX IjsJECJaVQIpKltL GxAVKBZePFsRUQkR aAdMdwAUHlAWAgsB AmAbWlFeU1h7WWA7 bghPaBtcak9QXgdq T0pMXVMcUQQbd3YD A2EeWxx3dAEIfndx ZwhgCCEIDhcsJ1sp Q0cBCGwHMGJ9YGIW BV1YdwJRcQRDe0tA b1YxNiYHcQ5VPz4z GA41ejw8IwAXEyNb XkkDKkgRCUgKDnYy QApKFzEoFk5NWCQv LxwhLlIdGklZO1ku OFAiQjp/ X-Authentic-SMTP: 61633532353630.1037:706 X-AuthFastPath: 0 (Was 255) X-AuthSMTP-Origin: 52.5.185.120/25 X-AuthVirus-Status: No virus detected - but ensure you scan with your own anti-virus system. X-Spam-Status: No, score=-2.6 required=5.0 tests=BAYES_00,RCVD_IN_DNSWL_LOW autolearn=ham version=3.3.1 X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on smtp1.linux-foundation.org X-Mailman-Approved-At: Fri, 12 Feb 2016 15:36:22 +0000 Cc: Bitcoin Dev Subject: Re: [bitcoin-dev] Soft fork fix for block withholding attacks X-BeenThere: bitcoin-dev@lists.linuxfoundation.org X-Mailman-Version: 2.1.12 Precedence: list List-Id: Bitcoin Development Discussion List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Fri, 12 Feb 2016 15:35:11 -0000 --CE+1k2dSO48ffgeK Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Fri, Feb 12, 2016 at 10:31:56PM +1100, gladoscc via bitcoin-dev wrote: > Here's a method of fixing block withholding attacks with a soft fork: So, while you're technique I believe works, it's not a soft-fork, at least under the definition most of the Bitcoin dev/research community have been using. The reason is if it's adopted by a majority of hashing power, less than a majority of hashing power can create a chain that appears to be the most-work chain, from the perspective of non-adopting nodes. Those nodes would then be following a weaker chain. A better term for what you're proposing might be a "pseudo-soft-fork", given that you don't quite meet the requirements for a true soft-fork. Having said that, it may be the case that overall your technique still reduces risk compared to a simpler hard-fork implementation of the idea; more analysis is needed there. --=20 https://petertodd.org 'peter'[:-1]@petertodd.org 000000000000000006d243cee301d792809a7d4d00c13ac24b43d5e9548625e4 --CE+1k2dSO48ffgeK Content-Type: application/pgp-signature; name="signature.asc" Content-Description: Digital signature -----BEGIN PGP SIGNATURE----- iQGrBAEBCACVBQJWvfuZXhSAAAAAABUAQGJsb2NraGFzaEBiaXRjb2luLm9yZzAw MDAwMDAwMDAwMDAwMDAwNmQyNDNjZWUzMDFkNzkyODA5YTdkNGQwMGMxM2FjMjRi NDNkNWU5NTQ4NjI1ZTQvFIAAAAAAFQARcGthLWFkZHJlc3NAZ251cGcub3JncGV0 ZUBwZXRlcnRvZC5vcmcACgkQJIFAPaXwkfu0zAf/VFd40EtGxhDJlWv5i8s4zEz7 9CtjCWMqflJnpegNniPig05nTFDrGxhU/f3C8/mDk05Ooh/22AT3B3Q+F/iUlE/v Y6M/Kh+GJ9mdPT65JTLeX1loCExR9355bRQtW+ObENnTbMDg3O/EdTPfKO44NskN AXp9cUZV/2s68fFI6rMuvx7XMWaEgMWnoXMvpISP2ms4Z46i72VaDUJFcOnNK0ty fETnLdW6DB9QYNwNVc5Jocb1FkHTX86zCg0pbOIkVAKm5jybFo0CJbqD8+HROldB V4bW5aE9hgI6vlEiu2K9H0Am2Ko5E8tB7/0E5h8uZflOBmmhKERnQQvcNEZLoQ== =OY79 -----END PGP SIGNATURE----- --CE+1k2dSO48ffgeK--