From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from sog-mx-2.v43.ch3.sourceforge.com ([172.29.43.192] helo=mx.sourceforge.net) by sfs-ml-3.v29.ch3.sourceforge.com with esmtp (Exim 4.76) (envelope-from ) id 1VhRXY-0006V4-U2 for bitcoin-development@lists.sourceforge.net; Fri, 15 Nov 2013 22:07:00 +0000 Received-SPF: pass (sog-mx-2.v43.ch3.sourceforge.com: domain of petertodd.org designates 62.13.149.113 as permitted sender) client-ip=62.13.149.113; envelope-from=pete@petertodd.org; helo=outmail149113.authsmtp.com; Received: from outmail149113.authsmtp.com ([62.13.149.113]) by sog-mx-2.v43.ch3.sourceforge.com with esmtp (Exim 4.76) id 1VhRXX-0000uV-2Z for bitcoin-development@lists.sourceforge.net; Fri, 15 Nov 2013 22:07:00 +0000 Received: from mail-c235.authsmtp.com (mail-c235.authsmtp.com [62.13.128.235]) by punt5.authsmtp.com (8.14.2/8.14.2) with ESMTP id rAFM6qam061346; Fri, 15 Nov 2013 22:06:52 GMT Received: from petertodd.org (petertodd.org [174.129.28.249]) (authenticated bits=128) by mail.authsmtp.com (8.14.2/8.14.2/) with ESMTP id rAFM6nrE074900 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES128-SHA bits=128 verify=NO); Fri, 15 Nov 2013 22:06:51 GMT Date: Fri, 15 Nov 2013 17:06:48 -0500 From: Peter Todd To: Mark Friedenbach Message-ID: <20131115220648.GA30456@petertodd.org> References: <20131104115314.GA1013@savin> <20131104181649.GA3847@petertodd.org> <5277F166.9090606@monetize.io> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha256; protocol="application/pgp-signature"; boundary="1yeeQ81UyVL57Vl7" Content-Disposition: inline In-Reply-To: <5277F166.9090606@monetize.io> User-Agent: Mutt/1.5.21 (2010-09-15) X-Server-Quench: 3b65e55a-4e42-11e3-b802-002590a15da7 X-AuthReport-Spam: If SPAM / abuse - report it at: http://www.authsmtp.com/abuse X-AuthRoute: OCd2Yg0TA1ZNQRgX IjsJECJaVQIpKltL GxAVKBZePFsRUQkR aAdMdwcUFloCAgsB AmUbWVZeUFt7XGE7 ag1VcwRfa1RMVxto VEFWR1pVCwQmQ213 exhAEGxycAFPeH4+ ZEdjVncVXxZ8cBN4 Rx9JETgCZ3phaTUc TRJQdwFJcANIexZF O1F6ACIKLwdSbGoL NQ4vNDcwO3BTJTpY RgYVKF8UXXNDNTk5 QhEeATQpEgUZQG0+ PwA8IxYWGEEaMQ0+ OEcoHltQORIOFgBE fQlIDTVWKhwERiwm RRhGVEgSGSdRKQAA X-Authentic-SMTP: 61633532353630.1023:706 X-AuthFastPath: 0 (Was 255) X-AuthSMTP-Origin: 174.129.28.249/587 X-AuthVirus-Status: No virus detected - but ensure you scan with your own anti-virus system. 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[URIs: petertodd.org] X-Headers-End: 1VhRXX-0000uV-2Z Cc: bitcoin-development@lists.sourceforge.net Subject: Re: [Bitcoin-development] Committing to extra block data/a better merge-mine standard X-BeenThere: bitcoin-development@lists.sourceforge.net X-Mailman-Version: 2.1.9 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Fri, 15 Nov 2013 22:07:01 -0000 --1yeeQ81UyVL57Vl7 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Mon, Nov 04, 2013 at 11:11:34AM -0800, Mark Friedenbach wrote: > > Now interpret the bits of that UUID as an allowed path: 0 =3D left, 1 > > =3D right, from the top of the tree. When you build the tree, make > > sure everything that is going to be committed to uses it's allowed > > path; the tree will look a bit jagged. If everyone picks their > > per-purpose UUIDs randomly the paths won't collide for very many > > levels on average, and path lengths will remain short. Validating > > that some given data was committed properly is simple and easy: > > just check the path, and check that the directions from the top of > > the tree followed the spec. >=20 > You mean... an authenticated prefix tree? Composable/commutative > properties are not needed as far as I can see, so you could make the > path validation, traversal, and proof size smaller by using level > compression. You don't need level compression if you adopt my per-block randomization idea. I think we'd be better off keeping the proofs as simple as possible, just dumb merkle paths. > I had previously proposed to this list a hash256-to-UUID mechanism > explicitly for this purpose. Recap: use 122 of the low 128 bits of the > aux-chain's genesis block to form a version=3D4 (random) or version=3D6 > (previously unused) UUID. However since making that proposal I am now > leaning towards simply using the hash of the genesis block directly to > identify aux chains since level compression will allow longer keys > with the same path length. I mentioned UUID more in spirit than in terms of the official UUID standard; any large randomly picked integer is fine. > If there is general interest, I can make finishing this a higher priority. Wouldn't hurt to run the idea past forrestv, given p2pool will be affected as it'd need to adopt the standard. He's run into some oddness with mining hardware and nonces that would be good to understand. (note how p2pool blocks don't commit to a fully random hash - there's some extra bytes in there due to stratum or something IIRC) --=20 'peter'[:-1]@petertodd.org 000000000000000601a5b2f2b4a597851fdf00f6fc3572bbc03f26857c170032 --1yeeQ81UyVL57Vl7 Content-Type: application/pgp-signature; name="signature.asc" Content-Description: Digital signature -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.11 (GNU/Linux) iQEcBAEBCAAGBQJShpr4AAoJEBmcgzuo5/CF28AIAJgCYIqmvnPTDkkzhEJnIeSP 5uB7vrLYYW26TUV5BBh0J6ssbVy4vcmQ2Weyyzil6pA1WeIajulNHipD1QDjQpCd 1mdfKwP56uWxllkfo9+EH4U+Z3GD+a9HGEF8QyLPIW5L1DqjzF1t0m5EbJRfqp4E NQeXhPSjnjgVTiWSWxCCOOS4gwU/JpX3e7PfQhnq7BZbLz6dxz0CWC4IIbFS9wSM FVGrvcO/u8arws46403y/mM+Nxg/kDe3Iw0ZD2eTadjUX2z7tqHHJcy1SNMUs/D4 opcBN2k0Q//ZsETlYynIFF9HDHUitP1aiQGSvawFEDOUNtowpSxhHnN1f7PHqi0= =RXaS -----END PGP SIGNATURE----- --1yeeQ81UyVL57Vl7--