From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from fraxinus.osuosl.org (smtp4.osuosl.org [140.211.166.137]) by lists.linuxfoundation.org (Postfix) with ESMTP id 1B698C004C for ; Sun, 2 Aug 2020 14:22:46 +0000 (UTC) Received: from localhost (localhost [127.0.0.1]) by fraxinus.osuosl.org (Postfix) with ESMTP id 038C985773 for ; Sun, 2 Aug 2020 14:22:46 +0000 (UTC) X-Virus-Scanned: amavisd-new at osuosl.org Received: from fraxinus.osuosl.org ([127.0.0.1]) by localhost (.osuosl.org [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id HTokgiu758l6 for ; Sun, 2 Aug 2020 14:22:44 +0000 (UTC) X-Greylist: domain auto-whitelisted by SQLgrey-1.7.6 Received: from mail-40140.protonmail.ch (mail-40140.protonmail.ch [185.70.40.140]) by fraxinus.osuosl.org (Postfix) with ESMTPS id 1D37A85168 for ; Sun, 2 Aug 2020 14:22:44 +0000 (UTC) Date: Sun, 02 Aug 2020 14:22:30 +0000 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=protonmail.com; s=protonmail; t=1596378161; bh=rGlD2thAD2dvkEK5XaAvFPPuBCADJMdGy7qxB0wNmXM=; h=Date:To:From:Cc:Reply-To:Subject:In-Reply-To:References:From; b=Ks0ADnBTOZ336/Oxm7ke13GHpGbkzrTbq9f6G4Xoie9cKs9AFAAhgB8SChPKnWU7U wEfaCD5FP5Tmj4FVQKN7wi+Je99ZK6qlP8BjphwCNLUSN8M09MWLSuCrT9iuqlkxPM brY1nxwAbTzWtYgd+ZoR3dAO661oAqw6zSO8igoA= To: Mike Brooks From: ZmnSCPxj Reply-To: ZmnSCPxj Message-ID: <-vfdrKtX7fPIncbPlX7CkHYD0NjZDz6VUjlkUrCO-feq3zaQpXRl8Wu_HP7CRXm1sc_p0B0IZjnTxiHfz_saXWL5W6ax9CVnddaDfPQvTBE=@protonmail.com> In-Reply-To: References: <1cxOISncF4dES_Ijm5FJUhwUAzBupnLPiv3qnU20as76zMMhVyggkg1hphq4ehuqEFK_H88TBbfI2pKbLWzzx7E6kOUXeC-yOcfrOkg3uAY=@protonmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable Cc: Bitcoin Protocol Discussion Subject: Re: [bitcoin-dev] Smaller Transactions with PubRef X-BeenThere: bitcoin-dev@lists.linuxfoundation.org X-Mailman-Version: 2.1.15 Precedence: list List-Id: Bitcoin Protocol Discussion List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Sun, 02 Aug 2020 14:22:46 -0000 Good morning Mike, The issue with SCRIPT re-evaluation is that reorgs cause more processing to= be done by nodes. Floating-point Nakamoto Consensus does not help here, since a node can rece= ive the lower-scored block first, and *then* a higher-scored block, and thu= s will ***still*** observe a reorg since the chain tip is replaced with a h= igher-scored block later. This still increases the processing load on validating fullnodes, and preve= nts any kind of pruning from working for validating fullnodes. A miner can also still mount a DoS on validating fullnodes, with `OP_PUBREF= ` and Floating-Point Nakamoto Consensus by re-mining the same block, and br= oadcasting a block if it has higher score than the previous chain tip. This locks the blockchain ***and*** increases the load on fullnodes, which = have to re-validate uses of `OP_PUBREF` that might refer to the chain tip. Regards, ZmnSCPxj > Hey=C2=A0 ZmnSCPxj, > > Re-orgs should be solved in a different=C2=A0way.=C2=A0 > > Best Regards, > Micahel > > On Sat, Aug 1, 2020 at 5:36 PM ZmnSCPxj wrote: > > > Good morning Mike, > > > > Hard NAK. > > > > The responses to the original posting already pointed out important pro= blems with this: > > > > * Encourages address reuse, hurting fungibility and privacy. > > * Prevents pruning, since access to previous blocks must always be avai= lable in order to validate. > > * Optimized implementation requires creating yet another index to previ= ous block data, increasing requirements on fullnodes. > > * Requires SCRIPT to be re-evaluated on transactions arriving in=C2= =A0 newblocks, to protect against reorgs of the chaintip, and in particular= `OP_PUBREF` references to near the chaintip. > > > > None of these issues have been addressed in your current proposal. > > The proposal looks at clients only, without considering what validators= have to implement in order to validate new blocks with this opcode. > > > > Regards, > > ZmnSCPxj