Return-Path: Received: from smtp1.linuxfoundation.org (smtp1.linux-foundation.org [172.17.192.35]) by mail.linuxfoundation.org (Postfix) with ESMTPS id 8A7B889C for ; Fri, 4 Dec 2015 16:47:00 +0000 (UTC) X-Greylist: whitelisted by SQLgrey-1.7.6 Received: from mail-qk0-f181.google.com (mail-qk0-f181.google.com [209.85.220.181]) by smtp1.linuxfoundation.org (Postfix) with ESMTPS id 234C914D for ; Fri, 4 Dec 2015 16:47:00 +0000 (UTC) Received: by qkda6 with SMTP id a6so46035288qkd.3 for ; Fri, 04 Dec 2015 08:46:59 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=subject:to:references:from:message-id:date:user-agent:mime-version :in-reply-to:content-type:content-transfer-encoding; bh=wt5ThvnB8aarRF0b8Vsc4uIy3vj5joUcIixmDiogePQ=; b=lqm/GYOMEK/QYigEDskNTTty5mmKedgjv1DK0ih5Qo2pC92Gzf+tx4Ppo+ybT6PV60 RwCb1MAX3BDYU0TTpAp5BgZqqr+WSIB9ctpgWN7fMdQdBLpBomg+Fpr9wJNqHjFajUsy GhuX4rVi7MPBJAlPq2QbAvA6d1ZoL8yDyf4iZ/dl2FxJSWs+Fmn9kcDMO0f9l02RxwWq wXJ/O7E+xHirKBzfcABhmuDuhfQK7QgGm1cvu9S1daRAJZ8i2KK0J+WOJL0RHTA2H4ll 3em9sLzo9KMYd7Y+DOWwZv3GZP+d5Zmhuv1elQHQuTTxsxPUwU5Wo8TQKhLczzhFxJ7p pidg== X-Received: by 10.55.77.202 with SMTP id a193mr19387632qkb.48.1449247619201; Fri, 04 Dec 2015 08:46:59 -0800 (PST) Received: from [192.168.0.3] ([82.223.30.165]) by smtp.gmail.com with ESMTPSA id e184sm5825110qkb.40.2015.12.04.08.46.57 for (version=TLSv1/SSLv3 cipher=OTHER); Fri, 04 Dec 2015 08:46:58 -0800 (PST) To: bitcoin-dev@lists.linuxfoundation.org References: From: Thomas Kerin X-Enigmail-Draft-Status: N1110 Message-ID: <5661C36A.9090509@gmail.com> Date: Fri, 4 Dec 2015 16:46:34 +0000 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:38.0) Gecko/20100101 Thunderbird/38.3.0 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: 7bit X-Spam-Status: No, score=-2.7 required=5.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID, DKIM_VALID_AU, FREEMAIL_FROM, RCVD_IN_DNSWL_LOW autolearn=ham version=3.3.1 X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on smtp1.linux-foundation.org X-Mailman-Approved-At: Fri, 04 Dec 2015 17:35:23 +0000 Subject: Re: [bitcoin-dev] Blockchain verification flag (BIP draft) X-BeenThere: bitcoin-dev@lists.linuxfoundation.org X-Mailman-Version: 2.1.12 Precedence: list List-Id: Bitcoin Development Discussion List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Fri, 04 Dec 2015 16:47:00 -0000 1. Not relaying can cause problems. Gossip networks operate by propagating new information (like a single new header), and refuse to relay information if it's obviously invalid. From the POV of a full node, which will normally hear about the header first, there's no point to not telling peers about this information. It's likely in the interest of SPV wallets to hear about EVERY contending chain, so they can go about their business deciding which is correct. 2. The only difference between a block and it's header is the list of transactions. There isn't anywhere else to put the flag but the header's version. Which is good, because clients usually receive headers first. 3. "Signal would need to include some sort of proof" That's not the point of this BIP. You can't prove the miner has or hasn't verified the chain. What purpose would it even serve? If clients accepted this 'proof', they might ignore blocks they should pay attention to. The BIP doesn't involve proof at all, it's just an indicator you can chose to use or ignore. On 04/12/15 12:44, Jannes Faber via bitcoin-dev wrote: > nodes side by side, one of them doesn't validate in order to reduce latency