Return-Path: Received: from smtp1.linuxfoundation.org (smtp1.linux-foundation.org [172.17.192.35]) by mail.linuxfoundation.org (Postfix) with ESMTPS id 4C6E7B66 for ; Mon, 8 May 2017 23:56:51 +0000 (UTC) X-Greylist: whitelisted by SQLgrey-1.7.6 Received: from mail-ua0-f170.google.com (mail-ua0-f170.google.com [209.85.217.170]) by smtp1.linuxfoundation.org (Postfix) with ESMTPS id D48E710A for ; Mon, 8 May 2017 23:56:50 +0000 (UTC) Received: by mail-ua0-f170.google.com with SMTP id j17so33131667uag.3 for ; Mon, 08 May 2017 16:56:50 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=mime-version:sender:in-reply-to:references:from:date:message-id :subject:to:cc; bh=EPSMAFBxhmmSL81pLyI77vxUxT6GmapYVnqNovsDaQI=; b=MHb8xGT+uURlCMyUYS4/EoKmU4e5k6eT8uSr1soPpzsQvvDjnZA4+YdumbWiy9JIHb tJ/7vtruQxtAKJ8R/WGkyXrhUlKoEYFLyiykaL35j/mLNODRwXWfSN8G52WbeKcIs35b 4aKl69CK6widXuORZcC3/6REygauPE/z+ohhxXTG6puAHH+y6Eoa/VbtrHLc1DrH798m BpcTwsKdPVC6PG4HymMoGqKkOkTgwcaRlq9ZvjgpDXgyTurz6C3pFqBoixT2qhRp7VMW 34D7RkpqWzE3nJwhIGua/zZlZ4hL6DF02hSIXWxLLRiIW71Kgt9WDyLufaXrsjBPiZ+M E/OA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:sender:in-reply-to:references:from :date:message-id:subject:to:cc; bh=EPSMAFBxhmmSL81pLyI77vxUxT6GmapYVnqNovsDaQI=; b=Qqwg1UPzIpKrJm5cnP9yst3jRYnN/I0pxy8QjcUgE6+/SYTeiSlmZpS7Kw5NIgcQci 2M2ErBYpeLqafqmo/tsRLtjkfZFV4sFiJpQRZVA07bbMmqR/olKp9ymMK4us7S/eVJz+ NdX0CwLL8PMR6D8WZpXhBHlmNimHa4IKhFzWlh7Sn3qaJT0OOCNGlCSKgdty+m0NvrXw QfxtAkqb9x7TxMcLjSCyNry+kFKus7VmylWR5yzHyEB7q/cJiiogXigu8niF6qU4Nfov js06cdNMuLL6AZ8nk3UTAXIoLmqdiFjhCWNYOt+hHBKvbdW3efsbXaF/hHdKwei9nJu+ PROQ== X-Gm-Message-State: AODbwcBrM3FlMnuFlDtInGhfTqL+VrLEMidF1fKjRwKIy317TcrRFP9t kvVvAdSfie/W+EL7UdmqR8EBnZKF6Q== X-Received: by 10.159.32.66 with SMTP id 60mr1858698uam.78.1494287810023; Mon, 08 May 2017 16:56:50 -0700 (PDT) MIME-Version: 1.0 Sender: gmaxwell@gmail.com Received: by 10.103.20.66 with HTTP; Mon, 8 May 2017 16:56:49 -0700 (PDT) In-Reply-To: References: From: Gregory Maxwell Date: Mon, 8 May 2017 23:56:49 +0000 X-Google-Sender-Auth: 7QFwUTdl4jHSsMnuk1WV8QWm284 Message-ID: To: Sergio Demian Lerner Content-Type: text/plain; charset=UTF-8 X-Spam-Status: No, score=-1.9 required=5.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID, FREEMAIL_FROM, 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 Cc: bitcoin-dev , hello@p2sh.info Subject: Re: [bitcoin-dev] Some real-world results about the current Segwit Discount 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: Mon, 08 May 2017 23:56:51 -0000 On Mon, May 8, 2017 at 10:42 PM, Sergio Demian Lerner via bitcoin-dev wrote: > The non-witness data weight factor should not be 4 but 2.35. The closest > integer value is 2, which leads to a 50% witness discount. Sergio, You've provided absolutely no information to qualify your "should be". It sounds like you are only measuring how much data is witness vs non-witness while completely ignoring the relative cost of UTXO bloat? It's perfectly acceptable to increase the worst case in one dimension while decreasing it in another-- and thats what segwit does. This sounds like a misunderstanding of what the factors should have accomplish. The non-witness factor should be as large as possible because the prunable witness data has little to no long term cost to the system, no cost to lite clients, etc-- as eventually the system's survival will require transitioning to starting from a state snapshot. But it cannot be too large because of the hyperbolic increase in worst case bandwidth. Also, when starting from a state snapshot security will require starting from an old one-- otherwise the whole system becomes much closer to SPV security, so the cost of witness data between there and the tip will still matter. If I had any leaning to adjust it, it would be towards five-- not towards even lower values. > The Bitcoinj source code is available for anyone to review. Where is it? (I have to say, I haven't found bitcoinj based things at all readable but it would be worth seeing.)