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 58335136E for ; Mon, 28 Sep 2015 14:43:24 +0000 (UTC) X-Greylist: from auto-whitelisted by SQLgrey-1.7.6 Received: from outmail148111.authsmtp.net (outmail148111.authsmtp.net [62.13.148.111]) by smtp1.linuxfoundation.org (Postfix) with ESMTP id 9C2DF232 for ; Mon, 28 Sep 2015 14:43:23 +0000 (UTC) Received: from mail-c235.authsmtp.com (mail-c235.authsmtp.com [62.13.128.235]) by punt18.authsmtp.com (8.14.2/8.14.2/) with ESMTP id t8SEhMPA076620; Mon, 28 Sep 2015 15:43:22 +0100 (BST) Received: from savin.petertodd.org (75-119-251-161.dsl.teksavvy.com [75.119.251.161]) (authenticated bits=128) by mail.authsmtp.com (8.14.2/8.14.2/) with ESMTP id t8SEhI5n041323 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES128-SHA bits=128 verify=NO); Mon, 28 Sep 2015 15:43:21 +0100 (BST) Date: Mon, 28 Sep 2015 10:43:18 -0400 From: Peter Todd To: Mike Hearn Message-ID: <20150928144318.GA28939@savin.petertodd.org> References: <20150927185031.GA20599@savin.petertodd.org> <20150928132127.GA4829@savin.petertodd.org> <20150928142953.GC21815@savin.petertodd.org> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha256; protocol="application/pgp-signature"; boundary="6TrnltStXW4iwmi0" Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.21 (2010-09-15) X-Server-Quench: 4419ff36-65ef-11e5-b399-002590a15da7 X-AuthReport-Spam: If SPAM / abuse - report it at: http://www.authsmtp.com/abuse X-AuthRoute: OCd2Yg0TA1ZNQRgX IjsJECJaVQIpKltL GxAVKBZePFsRUQkR aAdMdAoUC1AEAgsB AmMbWlFeVF57W2I7 bA9PbARUfEhLXhtr VklWR1pVCwQmRRRi c0ZnV0dycwRFen0+ Y0ViWj5fWEVzIxB+ RFNSEDhQeGZhPWUC AkNRfh5UcAFPdx8U a1UrBXRDAzANdhEy HhM4ODE3eDlSNhEd ZgwRYklaTUsTGjkt DzojJWtyVWYlag4Q CzsNCWI9OWsvH38T H2poMf9/ X-Authentic-SMTP: 61633532353630.1023:706 X-AuthFastPath: 0 (Was 255) X-AuthSMTP-Origin: 75.119.251.161/587 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 Cc: Bitcoin Dev Subject: Re: [bitcoin-dev] Let's deploy BIP65 CHECKLOCKTIMEVERIFY! 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: Mon, 28 Sep 2015 14:43:24 -0000 --6TrnltStXW4iwmi0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Mon, Sep 28, 2015 at 04:33:23PM +0200, Mike Hearn wrote: > > > > SPV wallets can't detect hard-forks >=20 >=20 > They don't have to - they pick the highest work chain. Any miner who hasn= 't > upgraded makes blocks on the shorter chain that are then ignored (or > rather, stored for future reorgs). After the fork point, there won't be a= ny > blocks in the main chain that violate the rules and end up being doomed to > being orphaned, which is the underlying problem. >=20 > And I think you know this already. There is no "flaw" in bitcoinj in this > respect. It works exactly as it was designed to work. Ok, so again, if that's your security criteria, what's the issue with soft-forks? With soft-forks, the result of a SPV wallet following the highest work chain is the same: eventually invalid blocks are reorged out. However, because soft-forks make it less likely that a long invalid chain will be generated, an attacker sybil attacking your SPV wallet has a much harder time tricking it into accepting a transaction. (they might get one or two confirmations, rather than dozens) What's the scenario where soft-forks are worse than hard-forks from a SPV wallet's perspective? --=20 'peter'[:-1]@petertodd.org 00000000000000000368227ec1de9c27c14d23cb7be9e9f38c0082db79a87c49 --6TrnltStXW4iwmi0 Content-Type: application/pgp-signature; name="signature.asc" Content-Description: Digital signature -----BEGIN PGP SIGNATURE----- iQGrBAEBCACVBQJWCVIDXhSAAAAAABUAQGJsb2NraGFzaEBiaXRjb2luLm9yZzAw MDAwMDAwMDAwMDAwMDAwMzY5MzY3MjlmYzE1Yjc0Yjc0ZTc3NGM5YmU5NDFjZTYx MDliZTI5NTIyNzY4NjUvFIAAAAAAFQARcGthLWFkZHJlc3NAZ251cGcub3JncGV0 ZUBwZXRlcnRvZC5vcmcACgkQJIFAPaXwkfu5cAf/Xm9b4TySAipd1PIj3JGF5QrX 6uoCL10rYeXv4ZVkRzo26+89grdSd3H9+BdSz3s8MgXY/F4mig4WZU5+aQXpFHoj qUShg9Qd1VNuQVQ02pGwz8+5ux0lsrSoPpYc7Vk+zQ1lgaCxgJAnm3hqXmiJwRsT ebDoFCrUbnqxgR03arXl7paGZcs4DtuGcO258hUU6VwFOoDDngGIFxy6EtH+zfSk Pffii0879CDuWsTpYJpj7c2KzIQMaowe8WivpgVIpZun2uV9Z2O04AxaOrGldyMT vQqDGYWlsm2OYjpnzzBMaQd+pHGihSjtKNtQcOlxnwNmqJeSHVa4bZZAIbR7qA== =19IV -----END PGP SIGNATURE----- --6TrnltStXW4iwmi0--