Return-Path: Received: from smtp4.osuosl.org (smtp4.osuosl.org [IPv6:2605:bc80:3010::137]) by lists.linuxfoundation.org (Postfix) with ESMTP id BD0D4C000B for ; Tue, 20 Apr 2021 01:22:54 +0000 (UTC) Received: from localhost (localhost [127.0.0.1]) by smtp4.osuosl.org (Postfix) with ESMTP id 9ED12402CA for ; Tue, 20 Apr 2021 01:22:54 +0000 (UTC) X-Virus-Scanned: amavisd-new at osuosl.org X-Spam-Flag: NO X-Spam-Score: -1.309 X-Spam-Level: X-Spam-Status: No, score=-1.309 tagged_above=-999 required=5 tests=[BAYES_00=-1.9, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RDNS_NONE=0.793, SPF_HELO_PASS=-0.001, SPF_PASS=-0.001] autolearn=no autolearn_force=no Authentication-Results: smtp4.osuosl.org (amavisd-new); dkim=pass (2048-bit key) header.d=cock.li Received: from smtp4.osuosl.org ([127.0.0.1]) by localhost (smtp4.osuosl.org [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id KvFgnJgToiJp for ; Tue, 20 Apr 2021 01:22:54 +0000 (UTC) X-Greylist: from auto-whitelisted by SQLgrey-1.8.0 Received: from mail.cock.li (unknown [37.120.193.123]) by smtp4.osuosl.org (Postfix) with ESMTPS id D5D0640254 for ; Tue, 20 Apr 2021 01:22:53 +0000 (UTC) MIME-Version: 1.0 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=cock.li; s=mail; t=1618881771; bh=UCulSLVFqyGYfmJ01hJNAN5IvHMAGhwe9L76zCG1zpU=; h=Date:From:To:Subject:In-Reply-To:References:From; b=0aNmG/rxWFhMzYYfVnWEGzOscugWDiRsQFMxOvDO0q8BIQmPHr5EhZeer7Ch3Fmcf vct3/UkGGSkW+/zElOPB+b0YIN9pZtK8WsWkZWmn2lilqlWWfZM8+G89Ul0FItYVFk el1E7rZcm1tv3DHPXqww2rZh2abyH0dgj5addzRLkCitg77q9lHsz6leV5jNZYoRPI Q8E16gcjk++9i6c1yM+6GRSKI50s/rZE6eoahPn99zzxDL0TANCYZivue06+czt1eb vP4Nk+sjsxpOEVJksVU3ufdn9jR4uZSLcukXtG3oAcA9zFgpSUrkpreAQh0fagWfVZ mdQIIIiwzPr4w== Content-Type: text/plain; charset=US-ASCII; format=flowed Content-Transfer-Encoding: 7bit Date: Tue, 20 Apr 2021 01:22:51 +0000 From: yanmaani@cock.li To: Christopher Gilliard , Bitcoin Protocol Discussion In-Reply-To: References: Message-ID: X-Sender: yanmaani@cock.li User-Agent: Roundcube Webmail/1.3.15 X-Mailman-Approved-At: Tue, 20 Apr 2021 02:28:34 +0000 Subject: Re: [bitcoin-dev] BIP - limiting OP_RETURN / HF 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: Tue, 20 Apr 2021 01:22:54 -0000 This has already been discussed and proposed in various papers and articles, typically to replace SHA-256d with something else. It basically works, but there's a some tiny issues: 1) Who goes first? If you first calculate the expensive PoW and then do a cheap SHA-256d around it, anyone can malleate it by changing the outer PoW. If you first calculate the cheap SHA-256d and then do an expensive PoW around it, it would work, but then you would have to retool the P2P protocol. 2) What's the incentive for miners? In a "normal" soft-fork, miners have the incentive to upgrade because their blocks will be orphaned if they don't, and even the old clients won't accept them. Here, miners will be able to produce an alternate chain that will appear valid to old clients, and that the new miners won't be able to orphan (since their hash power is much weaker).