<oembed><type>rich</type><version>1.0</version><title>John Newbery [ARCHIVE] wrote</title><author_name>John Newbery [ARCHIVE] (npub1ap…608ff)</author_name><author_url>https://njump.me/npub1aprq807up25mkugnhlr9nc2jkqqxd3wyrct3uj0kzhsdunaj7q8s7608ff</author_url><provider_name>njump</provider_name><provider_url>https://njump.me</provider_url><html>📅 Original date posted:2020-05-05&#xA;📝 Original message:There doesn&#39;t seem to be anything in the original email that&#39;s specific to&#xA;BIP 157. It&#39;s a restatement of the arguments against light clients:&#xA;&#xA;- light clients are a burden on the full nodes that serve them&#xA;- if light clients become more popular, there won&#39;t be enough full nodes to&#xA;serve them&#xA;- people might build products that depend on altruistic nodes serving data,&#xA;which is unsustainable&#xA;- maybe at some point in the future, light clients will need to pay for&#xA;services&#xA;&#xA;The choice isn&#39;t between people using light clients or not. People already&#xA;use light clients. The choice between whether we offer them a light client&#xA;technology that is better or worse for privacy and scalability.&#xA;&#xA;The arguments for why BIP 157 is better than the existing light client&#xA;technologies are available elsewhere, but to summarize:&#xA;&#xA;- they&#39;re unique for a block, which means they can easily be cached.&#xA;Serving a filter requires no computation, just i/o (or memory access for&#xA;cached filter/header data) and bandwidth. There are plenty of other&#xA;services that a full node offers that use i/o and bandwidth, such as&#xA;serving blocks.&#xA;- unique-for-block means clients can download from multiple sources&#xA;- the linked-headers/filters model allows hybrid approaches, where headers&#xA;checkpoints can be fetched from trusted/signed nodes, with intermediate&#xA;headers and filters fetched from untrusted sources&#xA;- less possibilities to DoS/waste resources on the serving node&#xA;- better for privacy&#xA;&#xA;&gt; The intention, as I understood it, of putting BIP157 directly into&#xA;bitcoind was to essentially force all `bitcoind` users to possibly service&#xA;BIP157 clients&#xA;&#xA;Please. No-one is forcing anyone to do anything. To serve filters, a node&#xA;user needs to download the latest version, set `-blockfilterindex=basic` to&#xA;build the compact filters index, and set `-peercfilters` to serve them over&#xA;P2P. This is an optional, off-by-default feature.&#xA;&#xA;Regards,&#xA;John&#xA;&#xA;&#xA;On Tue, May 5, 2020 at 9:50 AM ZmnSCPxj via bitcoin-dev &lt;&#xA;bitcoin-dev at lists.linuxfoundation.org&gt; wrote:&#xA;&#xA;&gt; Good morning ariard and luke-jr&#xA;&gt;&#xA;&gt;&#xA;&gt; &gt; &gt; Trust-minimization of Bitcoin security model has always relied first&#xA;&gt; and&#xA;&gt; &gt; &gt; above on running a full-node. This current paradigm may be shifted by&#xA;&gt; LN&#xA;&gt; &gt; &gt; where fast, affordable, confidential, censorship-resistant payment&#xA;&gt; services&#xA;&gt; &gt; &gt; may attract a lot of adoption without users running a full-node.&#xA;&gt; &gt;&#xA;&gt; &gt; No, it cannot be shifted. This would compromise Bitcoin itself, which for&#xA;&gt; &gt; security depends on the assumption that a supermajority of the economy is&#xA;&gt; &gt; verifying their incoming transactions using their own full node.&#xA;&gt; &gt;&#xA;&gt; &gt; The past few years has seen severe regressions in this area, to the point&#xA;&gt; &gt; where Bitcoin&#39;s future seems quite bleak. Without serious improvements&#xA;&gt; to the&#xA;&gt; &gt; full node ratio, Bitcoin is likely to fail.&#xA;&gt; &gt;&#xA;&gt; &gt; Therefore, all efforts to improve the &#34;full node-less&#34; experience are&#xA;&gt; harmful,&#xA;&gt; &gt; and should be actively avoided. BIP 157 improves privacy of fn-less&#xA;&gt; usage,&#xA;&gt; &gt; while providing no real benefits to full node users (compared to more&#xA;&gt; &gt; efficient protocols like Stratum/Electrum).&#xA;&gt; &gt;&#xA;&gt; &gt; For this reason, myself and a few others oppose merging support for BIP&#xA;&gt; 157 in&#xA;&gt; &gt; Core.&#xA;&gt;&#xA;&gt; BIP 157 can be implemented as a separate daemon that processes the blocks&#xA;&gt; downloaded by an attached `bitcoind`, i.e. what Wasabi does.&#xA;&gt;&#xA;&gt; The intention, as I understood it, of putting BIP157 directly into&#xA;&gt; bitcoind was to essentially force all `bitcoind` users to possibly service&#xA;&gt; BIP157 clients, in the hope that a BIP157 client can contact any arbitrary&#xA;&gt; fullnode to get BIP157 service.&#xA;&gt; This is supposed to improve to the situation relative to e.g. Electrum,&#xA;&gt; where there are far fewer Electrum servers than fullnodes.&#xA;&gt;&#xA;&gt; Of course, as ariard computes, deploying BIP157 could lead to an effective&#xA;&gt; DDoS on the fullnode network if a large number of BIP157 clients arise.&#xA;&gt; Though maybe this will not occur very fast?  We hope?&#xA;&gt;&#xA;&gt; It seems to me that the thing that *could* be done would be to have&#xA;&gt; watchtowers provide light-client services, since that seems to be the major&#xA;&gt; business model of watchtowers, as suggested by ariard as well.&#xA;&gt; This is still less than ideal, but maybe is better than nothing.&#xA;&gt;&#xA;&gt; Regards,&#xA;&gt; ZmnSCPxj&#xA;&gt; _______________________________________________&#xA;&gt; bitcoin-dev mailing list&#xA;&gt; bitcoin-dev at lists.linuxfoundation.org&#xA;&gt; https://lists.linuxfoundation.org/mailman/listinfo/bitcoin-dev&#xA;&gt;&#xA;-------------- next part --------------&#xA;An HTML attachment was scrubbed...&#xA;URL: &lt;http://lists.linuxfoundation.org/pipermail/bitcoin-dev/attachments/20200505/be23bd38/attachment-0001.html&gt;</html></oembed>