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 2864EBED for ; Thu, 16 Mar 2017 00:25:06 +0000 (UTC) X-Greylist: from auto-whitelisted by SQLgrey-1.7.6 Received: from cock.li (cock.li [185.100.85.212]) by smtp1.linuxfoundation.org (Postfix) with ESMTPS id E23E516A for ; Thu, 16 Mar 2017 00:25:04 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on smtp1.linux-foundation.org X-Spam-Level: X-Spam-Status: No, score=-2.0 required=5.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU autolearn=ham version=3.3.1 MIME-Version: 1.0 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=cock.lu; s=mail; t=1489623901; bh=crxzTR2TXDj0MR5EnXHeL+F7Gd7Uv02Nddmw8mbRqDI=; h=Date:From:To:Subject:In-Reply-To:References:From; b=dfjzyjYdMBqL+gUMKPV0E5/nORF2fM8rL6ocDERxK6x0UzzsfmL8O+7S/gjtb9Fzo TW+HC7TLNvIadrMmqQ4tgqd/QnS8qaYn1y9x+3pB3uqK5ZQhuOA7Bk7IQY/Zb/ImG1 MAgevCAy9Oi8OXREA3h4m97HqRPiK2gayBCd63CNGOj5uvpG867iQ4u66oqjIfnsGd pCAmGqTl5yy8FaT1SN6zRupc7t2bLxsYNgQDJIEek8Qnb3t9lIIN/rDobEG1x/fNo8 HX2HDAol5WZpu5IS6R+c6Av0redYLzgL2z6in3gAoZ1jm+O+EgooFVWmaMACU1YMoA o28iU4Cpbl4nQ== Content-Type: text/plain; charset=US-ASCII; format=flowed Content-Transfer-Encoding: 7bit Date: Thu, 16 Mar 2017 11:25:01 +1100 From: bfd@cock.lu To: Tom Harding , Bitcoin Protocol Discussion In-Reply-To: <7794520b-43a0-3227-1a68-58d12e432291@thinlink.com> References: <71d822e413ac457a530e1c367811cc24@cock.lu> <77b6dd25-0603-a0bd-6a9e-38098e5cb19d@jonasschnelli.ch> <74aeb4760316b59a3db56c0d16d11f28@cock.lu> <045843cb19f03888da10d2954cd1c685@cock.lu> <7794520b-43a0-3227-1a68-58d12e432291@thinlink.com> Message-ID: <48d3940ab1a2bd53c6e056ce7fbcd361@cock.lu> X-Sender: bfd@cock.lu User-Agent: Roundcube Webmail/1.2.3 X-Mailman-Approved-At: Thu, 16 Mar 2017 00:51:22 +0000 Subject: Re: [bitcoin-dev] Committed bloom filters for improved wallet performance and SPV security X-BeenThere: bitcoin-dev@lists.linuxfoundation.org X-Mailman-Version: 2.1.12 Precedence: list List-Id: Bitcoin Protocol Discussion List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Thu, 16 Mar 2017 00:25:06 -0000 Sorry, this is not the case. Your slides gloss over the simple fact that compact fraud proofs in Bitcoin aren't possible, and that the "SPV" implemented today bears absolutely no resemblance in security properties to the version described in the Bitcoin white paper. In the white paper SPV clients have the same security as fully validating nodes, in the implementation of BIP37 they have absolutely no security except the vague hope that they are not being lied to, and that the chain with the most work they are seeing is actually valid, both are very weak assumptions. The suggested solution in no way precludes unconfirmed transactions from being used with a commitment scheme, my comments and others are just recognising that they are an almost useless indicator for people who aren't validating. During the validationless mining failure around the BIP66 activation miners produced 6 invalid blocks in a chain, and many more invalid blocks in isolated bursts for a period lasting several months. Due to the instability of the network you are completely unreasonable to accept anything except multiple confirmations, the true number for safety is probably more like 60 or 120, not 6, or 3, or 1 as some Bitcoin exchanges use today. 0000000000000000009cc829aa25b40b2cd4eb83dd498c12ad0d26d90c439d99.bin bad-version(0x00000002) 0000000000000000032527aa796d3672e32e5f85a452d3a584a28fc7efbcd5d0.bin bad-version(0x00000002) 000000000000000003ae1223f4926ec86100885cfe1484dc52fd67e042a19b12.bin bad-version(0x00000002) 0000000000000000083cbdbb25c1607527c8f3fdb16f0d048c4439a73b501cb6.bin bad-version(0x00000002) 00000000000000000954ed93eda1e79e8261137548fa9ccf4d516bb384a3660b.bin bad-version(0x00000002) 00000000000000000afc9fbe7cfe8a6b50502d509ba626beb2e2d6c15d1d3ee3.bin bad-version(0x00000002) 00000000000000000b6adf92bc192b3c21210f456ab21b5e46951665c74cfab2.bin bad-version(0x00000002) 00000000000000000c9bb4a508fff34f5450d9c62ef2cb833e53909a4c549de5.bin bad-version(0x00000002) 0000000000000000116322b5f25826787b01f7a70fb322837b68dff8216cefc4.bin bad-version(0x00000002) 000000000000000012aac0664cd8b6cbc3ea485921a05f2c4340f928b0226d3c.bin bad-version(0x00000002) "SPV" like you're describing can exist, or validationless mining can exist, both can not simultaneously. On 2017-03-16 09:36, Tom Harding via bitcoin-dev wrote: > Agreed. > > In contrast, BIP37 as used today is totally decentralized, and can me > made much more secure, private, and scalable -- without giving up the > utility of unconfirmed transactions. > > Please don't read into this statement a belief that all the coffees > should go on the chain, or that the security or privacy of BIP37 > compare favorably to any other particular thing. > > https://docs.google.com/presentation/d/13MzUo2iIH9JBW29TgtPMoaMXxeEdanWDfi6SlfO-LlA > > > > On 1/5/2017 6:04 PM, bfd--- via bitcoin-dev wrote: >> You might as well replace Bitcoin with a system where these parties >> sign transactions and skip mining altogether, it would have the same >> properties and be significantly more effient. >> >> >> On 2017-01-04 23:06, Chris Priest wrote: >>> On 1/3/17, Jonas Schnelli via bitcoin-dev >>> wrote: >>>> >>>> There are plenty, more sane options. If you can't run your own >>>> full-node >>>> as a merchant (trivial), maybe co-use a wallet-service with >>>> centralized >>>> verification (maybe use two of them), I guess Copay would be one of >>>> those wallets (as an example). Use them in watch-only mode. >>> >>> The best way is to connect to the mempool of each miner and check to >>> see if they have your txid in their mempool. >>> >>> https://www.antpool.com/api/is_in_mempool?txid=334847bb... >>> https://www.f2pool.com/api/is_in_mempool?txid=334847bb... >>> https://bw.com/api/is_in_mempool?txid=334847bb... >>> https://bitfury.com/api/is_in_mempool?txid=334847bb... >>> https://btcc.com/api/is_in_mempool?txid=334847bb... >>> >>> If each of these services return "True", and you know those services >>> so not engage in RBF, then you can assume with great confidence that >>> your transaction will be in the next block, or in a block very soon. >>> If any one of those services return "False", then you must assume >>> that >>> it is possible that there is a double spend floating around, and that >>> you should wait to see if that tx gets confirmed. The problem is that >>> not every pool runs such a service to check the contents of their >>> mempool... >>> >>> This is an example of mining centralization increasing the security >>> of >>> zero confirm. If more people mined, this method will not work as well >>> because it would require you to call the API of hundreds of different >>> potential block creators. >> > > _______________________________________________ > bitcoin-dev mailing list > bitcoin-dev@lists.linuxfoundation.org > https://lists.linuxfoundation.org/mailman/listinfo/bitcoin-dev