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 652A5114E for ; Tue, 25 Sep 2018 21:55:55 +0000 (UTC) X-Greylist: whitelisted by SQLgrey-1.7.6 Received: from APC01-PU1-obe.outbound.protection.outlook.com (mail-oln040092254060.outbound.protection.outlook.com [40.92.254.60]) by smtp1.linuxfoundation.org (Postfix) with ESMTPS id B936C79F for ; Tue, 25 Sep 2018 21:55:52 +0000 (UTC) Received: from SG2APC01FT007.eop-APC01.prod.protection.outlook.com (10.152.250.58) by SG2APC01HT049.eop-APC01.prod.protection.outlook.com (10.152.250.250) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256_P256) id 15.20.1185.13; Tue, 25 Sep 2018 21:55:49 +0000 Received: from PS2P216MB0179.KORP216.PROD.OUTLOOK.COM (10.152.250.55) by SG2APC01FT007.mail.protection.outlook.com (10.152.250.84) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA384_P256) id 15.20.1185.13 via Frontend Transport; Tue, 25 Sep 2018 21:55:49 +0000 Received: from PS2P216MB0179.KORP216.PROD.OUTLOOK.COM ([fe80::6591:4009:39aa:1a22]) by PS2P216MB0179.KORP216.PROD.OUTLOOK.COM ([fe80::6591:4009:39aa:1a22%9]) with mapi id 15.20.1164.024; Tue, 25 Sep 2018 21:55:49 +0000 From: Damian Williamson To: Dave Scotese , "bitcoin-dev@lists.linuxfoundation.org" Thread-Topic: [bitcoin-discuss] Proposal to replace full blockchain with recent history plus UTXO Set Thread-Index: AQHUVOcOYgg0zCES50SnHptSoISXV6UBiRCQ Date: Tue, 25 Sep 2018 21:55:49 +0000 Message-ID: References: , In-Reply-To: Accept-Language: en-AU, en-US Content-Language: en-AU X-MS-Has-Attach: X-MS-TNEF-Correlator: x-incomingtopheadermarker: OriginalChecksum:6DD415203F223C9333B356786D604C9BD0324266C22EF421E5F2A00AA1F8D582; UpperCasedChecksum:E4D1C45E62C0B75C7F3E982B2DC406788650C7A4B7A7373E5DA27290C085A3C5; SizeAsReceived:7297; Count:46 x-ms-exchange-messagesentrepresentingtype: 1 x-tmn: [yjBLg1k5EHewB/E3ycaOc4pUFPrVvDPe] x-ms-publictraffictype: Email x-microsoft-exchange-diagnostics: 1; SG2APC01HT049; 6:UoACer4ZpCVg0ryi+ah/HVY+Do421QmtSRXt6EdDT4FBvzpufB3JhRbTl3sYitzDbq1UgQlaCaiiGGzEAXt4SsEX0lqXgx4nOn1K6DM6djwdjlL111t0LEFJHQ+9jS+vgHJz/aTLMY1EfRnn7DyxECJRxMQ43hu6K4nB16NDZXplA1Ntg3EQf7jbG6QJPxMCiClkfoS+G/VI86ovYkDnBQf4pYXc7GsasxqeZaDZ42ZIDh+BUyYw9+WSzBXpmontPXA0SJEuSCciOaTdyXwDYwIC+ffviEx7ajIwhgSg+63GlUNcHjs/EcR/nJlDhZzhCnI21LhQXFOLyH4YNoJhVNcFS25I8FW+GS7qAXvvkpW/W/1qZON54LkHPS83p4Gjh0auffqGiIzQd/cXfhehTVSweKuNoJd+YiUFojE43fZskWC7pMvwPy0ay4HYMnjiaDm1Ah93VioLAqNAKXiC2w==; 5:TAzW5RweaLFNP63ekNIjo0mYJAUb1u+8EqWUipsINoO8sd9CW8YulOTvnIvuGy9hCzXZvDG9jYcv9+JHScu9C4lw1jIT3emPKpoF1S9yMMRnA8DXDf6ZNU5WzwX6g9yjERmM29hBxY2E7q1wdM0CmrgGidjy23lXY1/xnpGvVNE=; 7:UG/W1czoefFQnrRholw0dJIBizGPuCVjwsCggY8yV/48c5aenJgV9Bdm9+WLKNm/x4PWfP799JvBrRyq17Vv2Va51+EwJtCzY8heXFmfcpK/55CY+hluuIOVn+WAibzrZc1vVCOCKMBkFi4qjJd0brwsFUwenvtH7JxZ42dKEG7t2rEAI2B0ntBt1n7FTkkVeS9qEb716V3Zh+kjNW8ALdgav+GbY4FZ1qLH7WORsTsp77Bs8ZWv/w1IFa4DwnQ4 x-incomingheadercount: 46 x-eopattributedmessage: 0 x-microsoft-antispam: BCL:0; PCL:0; RULEID:(7020095)(201702061078)(5061506573)(5061507331)(1603103135)(2017031320274)(2017031324274)(2017031323274)(2017031322404)(1603101475)(1601125500)(1701031045); SRVR:SG2APC01HT049; x-ms-traffictypediagnostic: SG2APC01HT049: x-exchange-antispam-report-cfa-test: BCL:0; PCL:0; RULEID:(4566010)(82015058); SRVR:SG2APC01HT049; BCL:0; PCL:0; RULEID:; SRVR:SG2APC01HT049; x-forefront-prvs: 08062C429B x-forefront-antispam-report: SFV:NSPM; SFS:(7070007)(52314003)(199004)(189003)(5250100002)(2501003)(9686003)(74482002)(236005)(6306002)(68736007)(54896002)(561944003)(551934003)(110136005)(14454004)(8936002)(6606003)(26005)(53386004)(6246003)(6346003)(33656002)(97736004)(66574007)(19627405001)(81156014)(606006)(55016002)(82202002)(102836004)(53546011)(25786009)(6506007)(53376002)(7696005)(229853002)(76176011)(7066003)(99286004)(5660300001)(71190400001)(34290500001)(71200400001)(14971765001)(966005)(56003)(256004)(105586002)(2900100001)(14444005)(106356001)(104016004)(74316002)(11346002)(446003)(476003)(21615005)(6436002)(86362001)(575784001)(486006)(10126625002)(15519875005)(9944002); DIR:OUT; SFP:1901; SCL:1; SRVR:SG2APC01HT049; H:PS2P216MB0179.KORP216.PROD.OUTLOOK.COM; FPR:; SPF:None; PTR:InfoNoRecords; A:1; MX:1; received-spf: None (protection.outlook.com: live.com.au does not designate permitted sender hosts) authentication-results: spf=none (sender IP is ) smtp.mailfrom=willtech@live.com.au; x-microsoft-antispam-message-info: /FcJU6C2jyB/gOQ6ItzPRtJySnOKyE0nvM/c574am3aXA2ZlH7eoGP1hHfs6KfjwdSj6skRnEgOQowMeMJP0IAs8LJ4Oa8Go/i5USxSbYYJzi6CcvOf0qLO69VKqA/+tfB7oTBXcLDAAb5r1ns//jYNonR9l1t+h00nU+MWIQU8zpjI+lSjeEWSmte72xXBATWuH4vJiFN/eLVaM2w7W/eZuz5KEgSGDXeWH1um+bpk= Content-Type: multipart/alternative; boundary="_000_PS2P216MB01795F6E52A18C73E20E9D5A9D160PS2P216MB0179KORP_" MIME-Version: 1.0 X-OriginatorOrg: outlook.com X-MS-Exchange-CrossTenant-RMS-PersistedConsumerOrg: c001924d-3e68-4f40-89c2-901a49278da7 X-MS-Exchange-CrossTenant-Network-Message-Id: 3b05f5a6-a827-4a02-87af-08d62331a7c4 X-MS-Exchange-CrossTenant-rms-persistedconsumerorg: c001924d-3e68-4f40-89c2-901a49278da7 X-MS-Exchange-CrossTenant-originalarrivaltime: 25 Sep 2018 21:55:49.3610 (UTC) X-MS-Exchange-CrossTenant-fromentityheader: Internet X-MS-Exchange-CrossTenant-id: 84df9e7f-e9f6-40af-b435-aaaaaaaaaaaa X-MS-Exchange-Transport-CrossTenantHeadersStamped: SG2APC01HT049 X-Spam-Status: No, score=-1.9 required=5.0 tests=BAYES_00,HTML_MESSAGE, RCVD_IN_DNSWL_NONE 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: Tue, 25 Sep 2018 23:52:17 +0000 Subject: Re: [bitcoin-dev] [bitcoin-discuss] Proposal to replace full blockchain with recent history plus UTXO Set 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: Tue, 25 Sep 2018 21:55:55 -0000 --_000_PS2P216MB01795F6E52A18C73E20E9D5A9D160PS2P216MB0179KORP_ Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: quoted-printable A fairly decent rework would be needed but it seems that the idea has merit= initially. As it is now, it is not only that a utxo exists but, that the transaction i= t references and the block it is within can also be fully validated. So, if a utxo block set type existed then by consensus every so often a bun= ch of blocks containing just the validated utxo set to a given height, say = 100,000 blocks below the current blockheight, and necessary header data cou= ld be appended onto the valid chain and nodes would be free to drop all pre= ceding blocks. I suspect that many wouldn't and that even many new nodes wo= uld still desire to download the full blockchain but, for the use case you = mention it would make sense. If done [right/wrong] it may even make Satoshi's fortune spendable. Somethi= ng to watch out for. ________________________________ From: bitcoin-discuss-bounces@lists.linuxfoundation.org on behalf of Dave Scotese via bitcoin-disc= uss Sent: Wednesday, 26 September 2018 1:46:54 AM To: Bitcoin Discuss Subject: Re: [bitcoin-discuss] Proposal to replace full blockchain with rec= ent history plus UTXO Set The image at imgur and the pastebin both reference block 542324 but the cor= rect block is 542322. As the pastebin shows, the decimal and hex represent= ations I gave for the block height did not match, and this is why. If you = use the Merkle root for block 542322 instead of 542324, you'll be able to s= ee the correct Game of Life play out and make the apron image. Dave. On Sun, Sep 23, 2018 at 11:38 AM Dave Scotese > wrote: I thought I didn't have access to the dev list and so intended to post the = following proposal to this discussion list, but used the wrong email addres= s. Anyway, my email did get into the dev list (https://lists.linuxfoundati= on.org/pipermail/bitcoin-dev/2018-September/016420.html) but I'll repeat it= here: I've been working on an idea that relieves full nodes of storing the entire= blockchain. Open source software generally relies on the fact that "enough= " people agree that it's secure. Bitcoin software works that way too. So if= you understand enough to see that a UTXO set is valid at a certain block h= eight, and there are enough other people who agree and that set is recogniz= able by humans, then we can use that UTXO set and ditch the blockchain that= existed up to that point. It would save a lot of storage and make it a lot= easier to run a full node. Have you reviewed the source code from which your wallets were compiled? At= some point, we all trust third parties, but generally (at least among peop= le who understand Bitcoin) they are large composite groups so that no small= group or individual can profit from cheating. I look forward to answering any concerns and also to any offers of help. = I used block 542324 of the Bitcoin blockchain to make a memorable experienc= e using the game of life. I wrote a script for the open-source Game-of-Life= software Golly and shared it in the paste at https://pastebin.com/k5Ssc0qk= . It produces the image at https://imgur.com/a/rwIQuVz. If someone can tell= me how to get a UTXO Set from the bitcoin client, I'll send them $50 of bi= tcoin. Then I could get the SHA256 hash of that set and try to make a recog= nizable checkpoint for the Bitcoin blockchain. If someone runs Golly and sh= ares a video of the game playing out (into the apron-shaped image), I'll se= nd them $50 of bitcoin too. In a few decades when the blockchain has grown to a few terabytes and the U= TXO Set is still just a few gigabytes, I'd like to see more people start ru= nning full nodes without the hassle of a long wait and loads of storage spa= ce. That's what stops me from running one. -- I like to provide some work at no charge to prove my value. Do you need a t= echie? I own Litmocracy and Meme Racing (in alpha). I'm the webmaster for The Voluntaryist which n= ow accepts Bitcoin. I also code for The Dollar Vigilante. "He ought to find it more profitable to play by the rules" - Satoshi Nakamo= to --_000_PS2P216MB01795F6E52A18C73E20E9D5A9D160PS2P216MB0179KORP_ Content-Type: text/html; charset="us-ascii" Content-Transfer-Encoding: quoted-printable

A fairly decent rework would be n= eeded but it seems that the idea has merit initially.


As it is now, it is not only that= a utxo exists but, that the transaction it references and the block it is = within can also be fully validated.


So, if a utxo block set type exis= ted then by consensus every so often a bunch of blocks containing just the = validated utxo set to a given height, say 100,000 blocks below the current = blockheight, and necessary header data could be appended onto the valid chain and nodes would be free to dro= p all preceding blocks. I suspect that many wouldn't and that even many new= nodes would still desire to download the full blockchain but, for the use = case you mention it would make sense.


If done [right/wrong] it may even= make Satoshi's fortune spendable. Something to watch out for.


From: bitcoin-discuss-bounc= es@lists.linuxfoundation.org <bitcoin-discuss-bounces@lists.linuxfoundat= ion.org> on behalf of Dave Scotese via bitcoin-discuss <bitcoin-discuss@lists.linuxfoundation.org>
Sent: Wednesday, 26 September 2018 1:46:54 AM
To: Bitcoin Discuss
Subject: Re: [bitcoin-discuss] Proposal to replace full blockchain w= ith recent history plus UTXO Set
 
The image at imgur and the pastebin both reference block 542324 but th= e correct block is 542322.  As the pastebin shows, the decimal and hex= representations I gave for the block height did not match, and this is why= .  If you use the Merkle root for block 542322 instead of 542324, you'll be able to see the correct Game of Life p= lay out and make the apron image.

Dave.

On Sun, Sep 23, 2018 at 11:38 AM Dave Scotese <dscotese@litmocracy.com> wrote:<= br>
I thought I didn't have access to the dev list and so inte= nded to post the following proposal to this discussion list, but used the w= rong email address.  Anyway, my email did get into the dev list (https://lists.linuxfoundation.org/pipermai= l/bitcoin-dev/2018-September/016420.html) but I'll repeat it here:

I've been working on an idea that relieves full nodes of s= toring the entire blockchain. Open source software generally relies on the = fact that "enough" people agree that it's secure. Bitcoin softwar= e works that way too. So if you understand enough to see that a UTXO set is valid at a certain block height, and there are e= nough other people who agree and that set is recognizable by humans, then w= e can use that UTXO set and ditch the blockchain that existed up to that po= int. It would save a lot of storage and make it a lot easier to run a full node.

Have you reviewed the source code from which your wallets were compiled? At= some point, we all trust third parties, but generally (at least among peop= le who understand Bitcoin) they are large composite groups so that no small= group or individual can profit from cheating.

I look forward to answering any concerns and also to any offers of help.&nb= sp;  I used block 542324 of the Bitcoin blockchain to make a memorable= experience using the game of life. I wrote a script for the open-source Ga= me-of-Life software Golly and shared it in the paste at h= ttps://pastebin.com/k5Ssc0qk. It produces the image at https://imgur.com= /a/rwIQuVz. If someone can tell me how to get a UTXO Set from the bitco= in client, I'll send them $50 of bitcoin. Then I could get the SHA256 hash = of that set and try to make a recognizable checkpoint for the Bitcoin blockchain. If someone runs Golly and shares a = video of the game playing out (into the apron-shaped image), I'll send them= $50 of bitcoin too.

In a few decades when the blockchain has grown to a few terabytes and the U= TXO Set is still just a few gigabytes, I'd like to see more people start ru= nning full nodes without the hassle of a long wait and loads of storage spa= ce. That's what stops me from running one.


--
I like to provide some work at no charge to prove my value= . Do you need a techie? 
I own Litmocracy and Meme Racing (in alpha).
I'm the webmaster for The Voluntaryist which now accepts Bitcoin.
I also code for T= he Dollar Vigilante.
"He ought to find it more profitable to play by the rules" - Sato= shi Nakamoto
--_000_PS2P216MB01795F6E52A18C73E20E9D5A9D160PS2P216MB0179KORP_--