Return-Path: Received: from smtp1.linuxfoundation.org (smtp1.linux-foundation.org [172.17.192.35]) by mail.linuxfoundation.org (Postfix) with ESMTPS id D4376ACB for ; Mon, 28 Aug 2017 17:55:01 +0000 (UTC) X-Greylist: whitelisted by SQLgrey-1.7.6 Received: from mail-vk0-f51.google.com (mail-vk0-f51.google.com [209.85.213.51]) by smtp1.linuxfoundation.org (Postfix) with ESMTPS id 0FC5187 for ; Mon, 28 Aug 2017 17:55:00 +0000 (UTC) Received: by mail-vk0-f51.google.com with SMTP id z187so3471274vkd.2 for ; Mon, 28 Aug 2017 10:55:00 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=rosenbaum-se.20150623.gappssmtp.com; s=20150623; h=mime-version:in-reply-to:references:from:date:message-id:subject:to; bh=A3jE+8iHEKpMscwFPByaYr4tb1qtB8S+HIsWDfy9Sos=; b=u9k771wbjVXU8oloQypBj+v54KYkQ9ISFFv9e/bCla2Dg+HPWWiXtxQgAyHIR9gn48 SwuyfE8itnsGaBy7Hx9crjM6z8QSHh1ZABwScui74yCRW/sRxolQNOoGXyZVrTIa7Fk8 mkLPvkgd4B8C7h51LrltCgyGNxgMvlDhRVWW2L1yXCbR2VEb/9f1o6qMz/bS0mbgLF44 H9HRnYEVtm59rD6oBE51KUwIabsJAlEp5ZmBZ45At3Ene0oiQTG4hGuUfas84Ii8a8Hg eeS2Z8LMUW0WwnVRRLwoRgdYjM5NZRe78oU9l+PX45dcRCYC3vs+mR18Gi2gCcnew5sF B7Xg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:in-reply-to:references:from:date :message-id:subject:to; bh=A3jE+8iHEKpMscwFPByaYr4tb1qtB8S+HIsWDfy9Sos=; b=AsI4qd/WTGf1iDL8C8/B4iVeNdRir5jParotQwaSWlJPoJ3vKtXIrV70KVd5ZkxueW 9BEqcaVvxlrWYsEW2+mQQVLUyXXrXbKKoBUE5LsNYWfKnfmNGlY2SMjR72e7K2iqXLUz c2+WFH2ae4Eb74oZOshbWOTAoSnOmjriS8KQ4OT6PhneK2ueR1V/F9nl/cSnoVfHggms q6vtoaYa9e6oCgxS7RYZZ+TJN9M05ViFS2lwYeEiLr1Rdzj2Os1x0oPzA6NHSBPERWAg 1YkiKo6Lw+unnnKNPAs6WoBD8uQg+JpJPS8ibD/Rq11wGBZQmmU4JmktNr1byFCjEzx8 O0ig== X-Gm-Message-State: AHYfb5ijuWTj1Qh+N+Z+jvYwrYTdKQGjUy5kn3XGSlO7r2a8iIgkfq6G Eaqcj8zmKSAFO8Zh9NK2ee4RyyUihiRfyszODA== X-Received: by 10.31.108.77 with SMTP id h74mr791393vkc.17.1503942900136; Mon, 28 Aug 2017 10:55:00 -0700 (PDT) MIME-Version: 1.0 Received: by 10.159.38.78 with HTTP; Mon, 28 Aug 2017 10:54:59 -0700 (PDT) In-Reply-To: References: From: Kalle Rosenbaum Date: Mon, 28 Aug 2017 19:54:59 +0200 Message-ID: To: Gregory Maxwell , Bitcoin Protocol Discussion Content-Type: multipart/alternative; boundary="001a114789645350890557d3fec4" X-Spam-Status: No, score=0.0 required=5.0 tests=DKIM_SIGNED,DKIM_VALID, HTML_MESSAGE,RCVD_IN_DNSWL_NONE autolearn=disabled version=3.3.1 X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on smtp1.linux-foundation.org X-Mailman-Approved-At: Mon, 28 Aug 2017 17:56:49 +0000 Subject: Re: [bitcoin-dev] Fwd: "Compressed" headers stream 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, 28 Aug 2017 17:55:01 -0000 --001a114789645350890557d3fec4 Content-Type: text/plain; charset="UTF-8" 2017-08-28 19:12 GMT+02:00 Gregory Maxwell via bitcoin-dev < bitcoin-dev@lists.linuxfoundation.org>: > > The bits field can only change every 2016 blocks (4 bytes per header), > the timestamp can not be less than the median of the last 11 and is > usually only a small amount over the last one (saves 2 bytes per > header), the block version is usually one of the last few (save 3 > bytes per header). > ... and I guess the nonce can be arbitrarily truncated as well, just brute force the missing bits :-P. > But all these things improvements are just a constant factor. I think > you want the compact SPV proofs described in the appendix of the > sidechains whitepaper which creates log scaling proofs. > I think that my blog post on compact spv proofs can be helpful also. It tries to make the pretty compact formulations in the sidechains paper a bit more graspable by normal people. http://popeller.io/index.php/2016/09/15/compact-spv-proofs/ Kalle --001a114789645350890557d3fec4 Content-Type: text/html; charset="UTF-8" Content-Transfer-Encoding: quoted-printable
2017= -08-28 19:12 GMT+02:00 Gregory Maxwell via bitcoin-dev &l= t;bitcoin-dev@lists.linuxfoundation.org>:

The bits field can only change every 2016 blocks (4 bytes per header),
the timestamp can not be less than the median of the last 11 and is
usually only a small amount over the last one (saves 2 bytes per
header), the block version is usually one of the last few (save 3
bytes per header).

=C2=A0... and I gues= s the nonce can be arbitrarily truncated as well, just brute force the miss= ing bits :-P.


But all these things improvements are just a constant factor. I think
you want the compact SPV proofs described in the appendix of the
sidechains whitepaper which creates log scaling proofs.

I think that my blog post on compact spv proofs can be hel= pful also. It tries to make the pretty compact formulations in the sidechai= ns paper a bit more graspable by normal people.=C2=A0

<= div>http://popeller.io/index.php/2016/09/15/compact-spv-proofs/=C2=A0

Kalle
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