Return-Path: Received: from smtp1.linuxfoundation.org (smtp1.linux-foundation.org [172.17.192.35]) by mail.linuxfoundation.org (Postfix) with ESMTPS id 83CB3FB9 for ; Thu, 31 Dec 2015 23:48:54 +0000 (UTC) X-Greylist: from auto-whitelisted by SQLgrey-1.7.6 Received: from outmail149056.authsmtp.com (outmail149056.authsmtp.com [62.13.149.56]) by smtp1.linuxfoundation.org (Postfix) with ESMTP id ABA98191 for ; Thu, 31 Dec 2015 23:48:53 +0000 (UTC) Received: from mail-c232.authsmtp.com (mail-c232.authsmtp.com [62.13.128.232]) by punt22.authsmtp.com (8.14.2/8.14.2/) with ESMTP id tBVNmqKL033303 for ; Thu, 31 Dec 2015 23:48:52 GMT Received: from muck (d23-16-73-171.bchsia.telus.net [23.16.73.171]) (authenticated bits=128) by mail.authsmtp.com (8.14.2/8.14.2/) with ESMTP id tBVNmmN5027899 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES128-SHA bits=128 verify=NO) for ; Thu, 31 Dec 2015 23:48:51 GMT Date: Thu, 31 Dec 2015 15:48:48 -0800 From: Peter Todd To: bitcoin-dev@lists.linuxfoundation.org Message-ID: <20151231234847.GB5112@muck> References: <20151223013119.GA31113@muck> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha256; protocol="application/pgp-signature"; boundary="yNb1oOkm5a9FJOVX" Content-Disposition: inline In-Reply-To: <20151223013119.GA31113@muck> X-Server-Quench: 0b95c785-b019-11e5-829e-00151795d556 X-AuthReport-Spam: If SPAM / abuse - report it at: http://www.authsmtp.com/abuse X-AuthRoute: OCd2Yg0TA1ZNQRgX IjsJECJaVQIpKltL GxAVJwpGK10IU0Fd P1hyKltILEZaQVBf Ri5dBBEKBAw1ADwr dVUTOkteY1U6ClZ1 UkhIR0JQFw9sCRYE B1AcUQdzcRtBe2Bx Ykd9W3hcQ0U0MTQb PBMJa2gGZ2BoYWlR U0Rddk1UIgpPLRhN b00tVHIEfGQGM399 T1ViMnVpZWwCcXsE Hw1QcAwEe0tZVg02 RgwJGjQpWEEIWRB7 FBEpMFMTFVocPg0t MEcnVEkDPgRaAwtS V19EBC5VLkUAQCwv ABhBFUsfFjxbTk8k X-Authentic-SMTP: 61633532353630.1037:706 X-AuthFastPath: 0 (Was 255) X-AuthSMTP-Origin: 23.16.73.171/587 X-AuthVirus-Status: No virus detected - but ensure you scan with your own anti-virus system. X-Spam-Status: No, score=-2.6 required=5.0 tests=BAYES_00,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 Subject: Re: [bitcoin-dev] Segregated witnesses and validationless mining 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: Thu, 31 Dec 2015 23:48:54 -0000 --yNb1oOkm5a9FJOVX Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Tue, Dec 22, 2015 at 05:31:19PM -0800, Peter Todd via bitcoin-dev wrote: > # Summary Updates from IRC discussion: 1) There was some debate about what exactly should be required from the current block to calculate the previous block posession proof. For instance, requiring the coinbase outputs potentially restricts some mining setups; requiring a commitment to the current block's (non-coinbase) transaction outputs restricts tx selection outsourcing schemes. However, it appears that we can allow the nonce to be picked arbitrarily. Equally, if the nonce is arbitrary, then a future soft-fork can be add commitments to current block contents. Thus the previous block proof can be simple H( + ) 2) Pieter Wuille brought up fraud proofs in relation to previous block content proofs - specifically how the simplest H( + ) construction requires a large fraud proof to prove incorrect. This followed a bunch of debate over what exactly fraud proofs would be - a proof that some data is fraudulent, or a unmet challenge that some data is correct? Regardless, if the posession proof is structured as a merkle tree, then fraud can be easily proven with a merkle path. In that model we'd take the previous block contents and rehash it in its entirety with the nonce. The fraud proof then becomes two merkle paths - one in the original block with the original hash, and the second with the same data, and same structure, but with the nonce mixed into the hashing algorithm. Todo: writeup the difference between the fraud proof model, and the validity challenge model, to provide background to making this decision. Incidentally, based the positive response to fixing this issue w/ segregated witnesses - my main objection to the plan - I've signed the Bitcoin Core capacity increases statement: https://github.com/bitcoin-dot-org/bitcoin.org/pull/1165#issuecomment-16826= 3005 --=20 'peter'[:-1]@petertodd.org 000000000000000006808135a221edd19be6b5b966c4621c41004d3d719d18b7 --yNb1oOkm5a9FJOVX Content-Type: application/pgp-signature; name="signature.asc" Content-Description: Digital signature -----BEGIN PGP SIGNATURE----- iQGrBAEBCACVBQJWhb7dXhSAAAAAABUAQGJsb2NraGFzaEBiaXRjb2luLm9yZzAw MDAwMDAwMDAwMDAwMDAwODE5YTE0NGYyNmZhOGVlNjQ0OTMyYWNhZmFkMGZmYzUw NDY5NDRkN2ZjNzY4MWIvFIAAAAAAFQARcGthLWFkZHJlc3NAZ251cGcub3JncGV0 ZUBwZXRlcnRvZC5vcmcACgkQwIXyHOf0udwZrQf+NnBXXNT1Bh+u54zdEO4uD+Im lU4JQGQbMY9nR12v23vgwtRGMamDQHVWg+CdhSDEhhJ+/vH85BouyCPUvrpki2yI ub3cwl1BQcv129e+ZgLQ8aoksP0xG9okDoEV1br04A+EtRKt+fEaxqJwo8b2KzA/ H4n30Oh5LE3d7qfMZvPv6iOSRWRWt06Eri8eNa1/r67sWTLZIys8FdubDFt0PJCo ARJGDfnIsGnoiYI4SlpzJZ5IQhNbqlX8QwgmIu7Jk0xILh6mbVBwbH0RuKOh3pLm HG9yF1z5DU8QRth7zXMBkLcRYXYPaB32tfNkrmVD8KAuMZjWHkoEsbtUlESlTw== =8toB -----END PGP SIGNATURE----- --yNb1oOkm5a9FJOVX-- From jtimon@jtimon.cc Sat Jan 2 16:37:56 2016 Return-Path: X-Original-To: bitcoin-dev@lists.linuxfoundation.org Delivered-To: bitcoin-dev@mail.linuxfoundation.org Received: from smtp1.linuxfoundation.org (smtp1.linux-foundation.org [172.17.192.35]) by mail.linuxfoundation.org (Postfix) with ESMTPS id 9A2181195 for ; Sat, 2 Jan 2016 16:37:56 +0000 (UTC) X-Greylist: whitelisted by SQLgrey-1.7.6 Received: from mail-vk0-f43.google.com (mail-vk0-f43.google.com [209.85.213.43]) by smtp1.linuxfoundation.org (Postfix) with ESMTPS id 170BA139 for ; Sat, 2 Jan 2016 16:37:55 +0000 (UTC) Received: by mail-vk0-f43.google.com with SMTP id f2so193970923vkb.3 for ; Sat, 02 Jan 2016 08:37:55 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=jtimon-cc.20150623.gappssmtp.com; s=20150623; h=mime-version:in-reply-to:references:date:message-id:subject:from:to :cc:content-type; bh=H0kkkEjwcr3KRE6+xcQ1cvr84swrAHCBj5OylmM/kV4=; b=A48lpFuKc+iCqOMuiqjlNSXgail9XRDw1aCGlHUKhtscHaUNmxh96LHsVE8v90r5SJ AIhkaJeaXnXkemp6gn21ir4vm1s0YRI8wmVV5kbV7UaFkY309q2pgjb80lyMwImYprsG +cVoUdqkJ2jQ7p7wfA7sD9TB++mWSM5k1URfQlY2zZheKQ6Jw0eVxu3zVYz57eF4YSQl /RUzOgxiPj4D5rzImdDqi22guvHS9MID8L0mfsVGl4JW98O6xSLlQuRz3dhHn7OEghFd 01R7zOAGxGaL7xEd93jmCPB4Z35htGG6p6VpbiMs0NZtu+kxaOilXwwtfbghiw+d8ZKK kVmQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20130820; h=x-gm-message-state:mime-version:in-reply-to:references:date :message-id:subject:from:to:cc:content-type; bh=H0kkkEjwcr3KRE6+xcQ1cvr84swrAHCBj5OylmM/kV4=; b=RsyFdMWvmV/ogpUr+sl7Hmff67lx/DRwtbjJ9bG6Au2Mg/KZL+b6MMJQp0g2ahUosd qtIn3mdA3AJAYkXKsLWwKLDJ0P1juWwOt9u2BvhQ8AMvB/mt55QqN3QhIcvhEuj7Vb3i Qg9n7T9XApZbx5r093IF4Dx9rQpgJyrWz+C1770wXbFWmtVVSGQz3o7975fCdn/GB0xQ zQtK6LgnCzNp2U51om2KJsKXHbtdn1dav0JAciIzG3gxHJrIyxPUrAd8yh5m6U87RAx8 AnoG1JTkEv0SFtT5yyDJTidZibm9fO/wgNaNwAo8sDVHuVX8fZAYJ27mjCWMBFq62ZKw peag== X-Gm-Message-State: ALoCoQkFMK7UYXXm+KwfdMYBpCQ2blZXieHOXtpDQ2LPSrwvF9bWFjtnUC2Irq2Jh34avf41O0n09sJBPBOFeAqZBcco5Wn7fQ== MIME-Version: 1.0 X-Received: by 10.31.154.213 with SMTP id c204mr55632144vke.38.1451752675201; Sat, 02 Jan 2016 08:37:55 -0800 (PST) Received: by 10.31.141.73 with HTTP; Sat, 2 Jan 2016 08:37:54 -0800 (PST) Received: by 10.31.141.73 with HTTP; Sat, 2 Jan 2016 08:37:54 -0800 (PST) In-Reply-To: <20151231234847.GB5112@muck> References: <20151223013119.GA31113@muck> <20151231234847.GB5112@muck> Date: Sat, 2 Jan 2016 17:37:54 +0100 Message-ID: From: =?UTF-8?B?Sm9yZ2UgVGltw7Nu?= To: Peter Todd Content-Type: multipart/alternative; boundary=001a1140f52c81ea1805285c825e X-Spam-Status: No, score=-2.6 required=5.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,HTML_MESSAGE,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 Cc: Bitcoin Dev Subject: Re: [bitcoin-dev] Segregated witnesses and validationless mining 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: Sat, 02 Jan 2016 16:37:56 -0000 --001a1140f52c81ea1805285c825e Content-Type: text/plain; charset=UTF-8 Is there a link to the IRC discussion? On Jan 1, 2016 12:49 AM, "Peter Todd via bitcoin-dev" < bitcoin-dev@lists.linuxfoundation.org> wrote: > > On Tue, Dec 22, 2015 at 05:31:19PM -0800, Peter Todd via bitcoin-dev wrote: > > # Summary > > Updates from IRC discussion: Is there a link to the IRC discussion? --001a1140f52c81ea1805285c825e Content-Type: text/html; charset=UTF-8

Is there a link to the IRC discussion?
On Jan 1, 2016 12:49 AM, "Peter Todd via bitcoin-dev" <bitcoin-dev@lists.linuxfoundation.org> wrote:
>
> On Tue, Dec 22, 2015 at 05:31:19PM -0800, Peter Todd via bitcoin-dev wrote:
> > # Summary
>
> Updates from IRC discussion:

Is there a link to the IRC discussion?

--001a1140f52c81ea1805285c825e--