From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from smtp2.osuosl.org (smtp2.osuosl.org [IPv6:2605:bc80:3010::133]) by lists.linuxfoundation.org (Postfix) with ESMTP id 4AFC2C000B for ; Sat, 24 Apr 2021 19:17:57 +0000 (UTC) Received: from localhost (localhost [127.0.0.1]) by smtp2.osuosl.org (Postfix) with ESMTP id 235E5400D2 for ; Sat, 24 Apr 2021 19:17:57 +0000 (UTC) X-Virus-Scanned: amavisd-new at osuosl.org X-Spam-Flag: NO X-Spam-Score: -2.1 X-Spam-Level: X-Spam-Status: No, score=-2.1 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, FREEMAIL_FROM=0.001, RCVD_IN_DNSWL_NONE=-0.0001, SPF_PASS=-0.001] autolearn=ham autolearn_force=no Authentication-Results: smtp2.osuosl.org (amavisd-new); dkim=pass (2048-bit key) header.d=gmail.com Received: from smtp2.osuosl.org ([127.0.0.1]) by localhost (smtp2.osuosl.org [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id w7wKni6XXBr5 for ; Sat, 24 Apr 2021 19:17:55 +0000 (UTC) X-Greylist: whitelisted by SQLgrey-1.8.0 Received: from mail-ed1-x532.google.com (mail-ed1-x532.google.com [IPv6:2a00:1450:4864:20::532]) by smtp2.osuosl.org (Postfix) with ESMTPS id 7A7944013E for ; Sat, 24 Apr 2021 19:17:55 +0000 (UTC) Received: by mail-ed1-x532.google.com with SMTP id bx20so59980079edb.12 for ; Sat, 24 Apr 2021 12:17:55 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :content-transfer-encoding; bh=ThcwX9DV01qS59d1Gu+OX7SIO73krz+mold1zrWx0oE=; b=Q+hUsChJf082EUP7M3rXLvoo44dLIpEYFdtJ+rjNReYQxgdK5Qmt/leffuk4UUJZHQ UjNKaVye/5onZptdHTvckWTPsu/I/EwCQJs2p8nyOLXNXNLbORRXWSFx/BY28h/LfTru FumsQDUz6uW6vfrHim/HLRnQLnq4Mb4JOE3GzjZXx/FixP7TFEvInIUAlC6Bjmf2aUTB 9zdspNU6fAWs+faIuDVqi2EFKSWcVnFpgoVEWoqUPVxopiWAdupRWn6p0o8+j6mpBJuB +0sCX5qCxmA0NrSYakbIjqMZgKGys/OyVb0CZjTII8HfapSc0FaonTUYJTFOxSp0Yxj8 NYgA== 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:content-transfer-encoding; bh=ThcwX9DV01qS59d1Gu+OX7SIO73krz+mold1zrWx0oE=; b=q6pm/GZ8dFo9xJQVZZqY/WJExTLyMi0eq4PuFZALavUODp8/o+gQte+eVLBvgDkd2q hyzAOXP0u9spVlujqAPc2SJH4D8DiIGokn+KQEiBmkcr4+XUPnfd6uPaNmZKNnSUsyA+ GpZSdcDHN8tA0+ej8NHF9/MC5qb+w9IHcnh+Q8Q6H3YmtDxipv5wogidvp5btouszmnM SEmYiETQpbedLWmYIUF+kW6H48L0dilPPimK+ycePwHc7ikA+xxvt6cFRmqWQ2z6FogO pccNxXQo2PEdKMj4ihT8akCgP3lQvMqSmf1WNHixVbiryB0jU7hwU0mQfeCRDHIxFbB1 fmTw== X-Gm-Message-State: AOAM533DmCuycRXNwXwLyFMMufdnk/yZZIjYHWhYOEIIOBk0V3EA8Kgd d7jtNOThee99pXzC8dChuO1xk/UwAZNY0D7qHVI= X-Google-Smtp-Source: ABdhPJzo6TI1xmpNY9fERs4J8N921FBQFexX4cd7lsSVIxpdK5nUKR7EdDznuXTaY/WuOUJ7Xu/YBpM8ZByrpL+2b3U= X-Received: by 2002:a05:6402:46:: with SMTP id f6mr11750377edu.252.1619291873701; Sat, 24 Apr 2021 12:17:53 -0700 (PDT) MIME-Version: 1.0 References: In-Reply-To: From: Greg Maxwell Date: Sat, 24 Apr 2021 19:17:41 +0000 Message-ID: To: NITSOPOULOS KONSTANTINOS , Bitcoin Protocol Discussion Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable X-Mailman-Approved-At: Sat, 24 Apr 2021 19:29:35 +0000 Subject: Re: [bitcoin-dev] 7z block compression, 18% 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: Sat, 24 Apr 2021 19:17:57 -0000 https://bitcointalk.org/index.php?topic=3D5303978.msg55946632#msg55946632 Blockstream satellite codebase includes an alternative serialization that works a single transaction at a time and saves ~20%. This avoids violating layering, preserves single txn access, is compatible with transaction relay. (and if you wanted could also be fed to a multiple txn at a time compressor for additional savings). This format makes intelligent use of the entirety of the transaction format, not just amount encodings but even optimizing predictable hashes (e.g. for p2sh embedded segwit) -- achieving savings that *no* generic compressor could ever achieve. Most of the savings from generic compressors comes from repeated pubkeys and addresses, so it's highly variable, depends on address reuse, and will likely be diminished by taproot (due to shrinking multisig) and very much reduced by signature aggregation in the future. If you're thinking about use across networks generic compression interfaces like zlib have had a pretty disappointing security track record. If you search the list archive and bitcoin-core github you'll find many prior discussions of using generic compressors. On Sat, Apr 24, 2021 at 6:12 PM NITSOPOULOS KONSTANTINOS via bitcoin-dev wrote: > > Hi, I can compress new blocks by up to 18% using the 7z file type. I use = wxHexEditor to dump a block's raw hex onto my disk, and then compress that = with 7-Zip. I'd like to see 7z built into Bitcoin Core, for block compressi= on (storage & propagation). The entire blockchain could be under 290GB if i= t's converted into a 7z archive-chain ("7z-chain"). I can compress some rec= ent example blocks (hex -> less hex) if anyone wants. A future BIP could tr= y increase the block Weight Units limit by up to 21% if 7z blocks are small= er & quick. > > Programming compression seems too difficult for me, so I'm hoping somebod= y else does it! > > Eventually I think transactions can be compressed by replacing addresses = (& public keys) and coins, wherever possible, with just their own unique se= quential index. TX amounts can also be compressed if they contain only a de= cimal digit or two, e.g. 00000000.10000000 XBT. A TX of 0.1 XBT between two= existing addresses could be somehow compressed to half or maybe a quarter = of its current size! > > -Tinos > _______________________________________________ > bitcoin-dev mailing list > bitcoin-dev@lists.linuxfoundation.org > https://lists.linuxfoundation.org/mailman/listinfo/bitcoin-dev