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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_--