Return-Path: Received: from smtp1.linuxfoundation.org (smtp1.linux-foundation.org [172.17.192.35]) by mail.linuxfoundation.org (Postfix) with ESMTPS id 8470FBE0 for ; Wed, 5 Sep 2018 03:10:11 +0000 (UTC) X-Greylist: delayed 00:09:15 by SQLgrey-1.7.6 Received: from mo.garage.hdemail.jp (mo.garage.hdemail.jp [46.51.242.127]) by smtp1.linuxfoundation.org (Postfix) with ESMTPS id 71217713 for ; Wed, 5 Sep 2018 03:10:09 +0000 (UTC) Received: from ip-10-217-1-36.ap-northeast-1.compute.internal (localhost.localdomain [127.0.0.1]) by mo.garage.hdemail.jp (hde-mf-postfix) with SMTP id AFAA114C0EE for ; Wed, 5 Sep 2018 12:00:52 +0900 (JST) (envelope-from karljohan-alm@garage.co.jp) X-Received: from unknown (HELO mo.garage.hdemail.jp) (127.0.0.1) by 0 with SMTP; 5 Sep 2018 12:00:52 +0900 X-Received: from mo.garage.hdemail.jp (localhost.localdomain [127.0.0.1]) by mo.garage.hdemail.jp (hde-ma-postfix) with ESMTP id A39DC4C086 for ; Wed, 5 Sep 2018 12:00:52 +0900 (JST) (envelope-from karljohan-alm@garage.co.jp) Received: from gw18.oz.hdemail.jp (ip-10-158-195-2.ap-northeast-1.compute.internal [10.158.195.2]) by mo.garage.hdemail.jp (hde-mf-postfix) with ESMTP id A12BF14C0EC for ; Wed, 5 Sep 2018 12:00:52 +0900 (JST) (envelope-from karljohan-alm@garage.co.jp) X-Received: from mail-qk1-f200.google.com (lb07.oz.hdemail.jp [54.238.57.67]) (using TLSv1 with cipher AES128-SHA (128/128 bits)) (No client certificate requested) by gw18.oz.hdemail.jp (Postfix) with ESMTP id 392B5148C0E0 for ; Wed, 5 Sep 2018 12:00:52 +0900 (JST) X-Received: by mail-qk1-f200.google.com with SMTP id e3-v6so4042534qkj.17 for ; Tue, 04 Sep 2018 20:00:52 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=wYi7P5ifmE2bnNOgjEttNmZeQfsIeVy1ut56XNhscnU=; b=hVPEMgukgoImojY41K7D+/BQo3kZMkO52sZl5mBK6rpHbyvrcSVYujwk9+bP6Yqjvv yb5ow6tkp8qhouIXFZyDpGzOmlzXefv0+HGhUSbWpTAl47chrYYFH2TpBy142LPpOh0H 9qdYYVzHR5HI7YFTNso3bT+CHx5C/kW0wyV7uAw63+9cJ951g2Gyvayl6NEP3VbU4BsM YwcKk7uxJhzTg4PVSOV6x3g6bnS4pEkqX6h3fB78MdoyyCRXZwVIq27Mca4r+u/f0Ado P0CXEx5rd4UI2hTaQTedI3JYmr4IP0De3APQdXwKR0CloXQtpw12ZHAnYsAYkGmaqjlQ nB9A== X-Gm-Message-State: APzg51ClFhi/iMvFSVKWuU7CTDbC75Em+/TIpdBCw+60DzmEk1yhmo4y j/xq60oVHMwYaq1xIvMeYykyESQR9cKdb7SWK3eLqytg3Sfc93CWlQ5CemAMelZHQUe0LJUOwcv jISFsRcGBinc1jUyZra7QBqI0MgTdC6z+mkwPF55OPXZoC8T1sjT+6cHjNR+Oxg3kEB4C9zSFiN nUnz6MywB0ZlkaRw8AQjyBTOXbX+l8ReVFWsh1nj6LGs1QmYIBAd/R8V/FKZ3+I5q/mmWeZ0Aht QFJQP/3J/5pLU54HiYaeBWeJCTp7gOSCQOvYX2sahgrPl4LVhLNUrsGk38AhuSnuGzy40cAV/F9 AzI/+SZywoiofToqVY00w7LPuXk= X-Received: by 2002:a37:1626:: with SMTP id g38-v6mr31179059qkh.176.1536116450791; Tue, 04 Sep 2018 20:00:50 -0700 (PDT) X-Google-Smtp-Source: ANB0VdYzf4hh0uxESq9XWxeBaEBqyqQVHpb6fiItxY1dQmSKLJqYQu9Yyp/nXWp3TGhXza8R7ERSOPePSDGUAcQM1Uw= X-Received: by 2002:a37:1626:: with SMTP id g38-v6mr31179043qkh.176.1536116450507; Tue, 04 Sep 2018 20:00:50 -0700 (PDT) MIME-Version: 1.0 References: <20180830200239.ujuzh7pitcuatdt3@petertodd.org> <7E247E56-38A5-4B99-941A-A2CC837D2567@xbt.hk> In-Reply-To: From: Karl-Johan Alm Date: Wed, 5 Sep 2018 12:00:39 +0900 Message-ID: To: Gregory Maxwell , Bitcoin Protocol Discussion Content-Type: text/plain; charset="UTF-8" X-Spam-Status: No, score=-1.9 required=5.0 tests=BAYES_00,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 X-Mailman-Approved-At: Wed, 05 Sep 2018 13:43:50 +0000 Cc: shiva@blockonomics.co Subject: Re: [bitcoin-dev] Testnet3 Reest 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: Wed, 05 Sep 2018 03:10:11 -0000 On Fri, Aug 31, 2018 at 9:43 PM Gregory Maxwell via bitcoin-dev wrote: > We looked at doing this previously in Bitcoin core and jtimon had some > patches, but the existing approach increased the size of the > blockindex objects in memory while not in signed testnet mode. This > could probably have been fixed by turning one of the fields like the > merkel root into a union of it's normal value and a pointer a > look-aside block index that is used only in signed block testnet mode. I am currently working on an implementation that simply puts a global mapping of block hash to signature that is transparently (de)serialized in the block header. We were looking into various ways to stuff the signature into the actual header itself without changing its size, but this looked like it required truncating the prevblock/merkleroots and such, which seemed a bit too invasive. I don't think my approach with a global mapping to sig differs in any meaningful way from your suggested union, but corrections welcome. The code is here: https://github.com/kallewoof/bitcoin/tree/signet I believe jtimon is interested in helping out, and Jeremy Rubin has also said he wants to help.