<oembed><type>rich</type><version>1.0</version><author_name>npub1nc78dlt7hp3v5dl32qu3m678h2j0ss374glcjnz8df75xcx7ngpq4gw452</author_name><author_url>https://nostr.ae/npub1nc78dlt7hp3v5dl32qu3m678h2j0ss374glcjnz8df75xcx7ngpq4gw452</author_url><provider_name>njump</provider_name><provider_url>https://nostr.ae</provider_url><html>📅 Original date posted:2013-07-17&#xA;📝 Original message:Hi Wendell,&#xA;&#xA;What Peter describes (a hash of the current set of UTXOs as part of the coinbase) is already implemented in libcoin, on which you can easily build both a bitcoind and any client. Libcoin is a library originally based on the satoshi client, and as such it is compatible/replacable with &#34;master&#34;. &#xA;&#xA;Have a look at github.com/libcoin/libcoin and look in the BlockChain.h/cpp and the MerkleTrie classes then you can see how it works.&#xA;&#xA;What is missing from libcoin is a scheme to bootstrap the hash of UTXOs, there is some stub code for a p2pool like mining scheme ensuring several UTXO hashes every 10 minutes, but I will not have time to finalize it the first few months - anyone are of course welcome to help out ;)&#xA;&#xA;Michael&#xA;&#xA;&#xA;On 17/07/2013, at 09:37, Wendell &lt;w at grabhive.com&gt; wrote:&#xA;&#xA;&gt; Peter,&#xA;&gt; &#xA;&gt; This sounds like a _very_ good idea for a desktop client, and probably acceptable to users so long as we take available disk space into consideration, and only ever use a fraction of it.&#xA;&gt; &#xA;&gt; Will you implement this?&#xA;&gt; &#xA;&gt; -wendell&#xA;&gt; &#xA;&gt; grabhive.com | twitter.com/grabhive&#xA;&gt; &#xA;&gt; On Jul 17, 2013, at 12:58 PM, Peter Todd wrote:&#xA;&gt; &#xA;&gt;&gt; So what&#39;s useful about that? Basically it means your node starts with&#xA;&gt;&gt; the same security level, and usefulness to the network, as a SPV node.&#xA;&gt;&gt; But over time you keep downloading blocks as they are created, and with&#xA;&gt;&gt; whatever bandwidth you have left (out of some user-configurable&#xA;&gt;&gt; allocation) you download additional blocks going further and further&#xA;&gt;&gt; back in time. Gradually your UTXO set becomes more complete, and over&#xA;&gt;&gt; time you can verify a higher and higher % of all valid transactions.&#xA;&gt;&gt; Eventually your node becomes a full node, but in the meantime it was&#xA;&gt;&gt; still useful for the user, and still contributed to the network by&#xA;&gt;&gt; relaying blocks and an increasingly large subset of all transactions.&#xA;&gt;&gt; (optionally you can store a subset of the chain history too for other&#xA;&gt;&gt; nodes to bootstrap from) You&#39;ve also got better security because you&#xA;&gt;&gt; *are* validating blocks, starting off incompletely, and increasingly&#xA;&gt;&gt; completely until your finally validating fully. Privacy is improved, for&#xA;&gt;&gt; both you and others, by mixing your transactions with others and adding&#xA;&gt;&gt; to the overall anonymity set.&#xA;&gt;&gt; &#xA;&gt;&gt; In the future we&#39;ll have miners commit a hash of the UTXO set, and that&#xA;&gt;&gt; gives us even more options to, for instance, have relayed transactions&#xA;&gt;&gt; include proof that their inputs were valid, allowing all nodes to relay&#xA;&gt;&gt; them safely.&#xA;&gt; &#xA;&gt; ------------------------------------------------------------------------------&#xA;&gt; See everything from the browser to the database with AppDynamics&#xA;&gt; Get end-to-end visibility with application monitoring from AppDynamics&#xA;&gt; Isolate bottlenecks and diagnose root cause in seconds.&#xA;&gt; Start your free trial of AppDynamics Pro today!&#xA;&gt; http://pubads.g.doubleclick.net/gampad/clk?id=48808831&amp;iu=/4140/ostg.clktrk_______________________________________________&#xA;&gt; Bitcoin-development mailing list&#xA;&gt; Bitcoin-development at lists.sourceforge.net&#xA;&gt; https://lists.sourceforge.net/lists/listinfo/bitcoin-development&#xA;&#xA;-------------- next part --------------&#xA;A non-text attachment was scrubbed...&#xA;Name: signature.asc&#xA;Type: application/pgp-signature&#xA;Size: 495 bytes&#xA;Desc: Message signed with OpenPGP using GPGMail&#xA;URL: &lt;http://lists.linuxfoundation.org/pipermail/bitcoin-dev/attachments/20130717/d6c0fe64/attachment.sig&gt;</html></oembed>