From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from smtp1.linuxfoundation.org (smtp1.linux-foundation.org [172.17.192.35]) by mail.linuxfoundation.org (Postfix) with ESMTPS id 4EF5B83D for ; Fri, 21 Aug 2015 05:42:31 +0000 (UTC) X-Greylist: from auto-whitelisted by SQLgrey-1.7.6 Received: from outmail148099.authsmtp.net (outmail148099.authsmtp.net [62.13.148.99]) by smtp1.linuxfoundation.org (Postfix) with ESMTP id 8E50DAB for ; Fri, 21 Aug 2015 05:42:30 +0000 (UTC) Received: from mail-c235.authsmtp.com (mail-c235.authsmtp.com [62.13.128.235]) by punt18.authsmtp.com (8.14.2/8.14.2/) with ESMTP id t7L5gTZh054391; Fri, 21 Aug 2015 06:42:29 +0100 (BST) Received: from muck ([24.114.27.112]) (authenticated bits=128) by mail.authsmtp.com (8.14.2/8.14.2/) with ESMTP id t7L5gKg2011738 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES128-SHA bits=128 verify=NO); Fri, 21 Aug 2015 06:42:28 +0100 (BST) Date: Thu, 20 Aug 2015 22:42:19 -0700 From: Peter Todd To: Matt Corallo , bitcoin-dev@lists.linuxfoundation.org Message-ID: <20150821054219.GB18176@muck> References: <55D6AD19.10305@mattcorallo.com> <20150821053819.GA18176@muck> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha256; protocol="application/pgp-signature"; boundary="dc+cDN39EJAMEtIO" Content-Disposition: inline In-Reply-To: <20150821053819.GA18176@muck> X-Server-Quench: 692447a8-47c7-11e5-b398-002590a15da7 X-AuthReport-Spam: If SPAM / abuse - report it at: http://www.authsmtp.com/abuse X-AuthRoute: OCd2Yg0TA1ZNQRgX IjsJECJaVQIpKltL GxAVKBZePFsRUQkR aAdMdAMUGUATAgsB AmMbW1JeVF97W2o7 aQ5PbARZfEhJQQRr UldMSlVNFUssBmAE UWVJUBlzdgJFcDB1 Y0VgEHZSXkB+chd1 X0pTRmobZGY1bX1N U0lQagNUcgZDfk5E bwQuUz1vNG8XDSg5 AwQ0PjZ0MThBHWxv Tx8MNlMOQEAEVhgb az01NxEIOmhXDx0p KAQhMVMQVGwwCi0A X-Authentic-SMTP: 61633532353630.1023:706 X-AuthFastPath: 0 (Was 255) X-AuthSMTP-Origin: 24.114.27.112/587 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] Revisiting NODE_BLOOM: Proposed BIP 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: Fri, 21 Aug 2015 05:42:31 -0000 --dc+cDN39EJAMEtIO Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Thu, Aug 20, 2015 at 10:38:19PM -0700, Peter Todd via bitcoin-dev wrote: > > Motivation > > =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D > >=20 > > BIP 37 did not specify a service bit for the bloom filter service, thus > > implicitly assuming that all nodes that serve peers data support it. > > However, the connection filtering algorithm proposed in BIP 37, and > > implemented in several clients today, has been shown to provide little > > to no privacy, as well as being a large DoS risk on some nodes. Thus, > > allowing node operators to disable connection bloom filtering is a > > much-needed feature. >=20 > I'd reference that paper on bloom filters re: the "little to no privacy" > issue. There's also a post in the bitcoinj mailing list somewhere IIRC > talking about the default settings, and how they don't provide any > privacy. Oh, and we should also point out that Bloom filters have scaling issues, as each application of the filter has to scan the whole blockchain - with future blocksize increases these issues increase, in some proposals quite dramatically. The underlying idea also conflicts with some proposals to "shard" the blockchain, again suggesting that we need a bit to handle future upgrades to more scalable designs. --=20 'peter'[:-1]@petertodd.org 00000000000000000402fe6fb9ad613c93e12bddfc6ec02a2bd92f002050594d --dc+cDN39EJAMEtIO Content-Type: application/pgp-signature; name="signature.asc" Content-Description: Digital signature -----BEGIN PGP SIGNATURE----- iQGrBAEBCACVBQJV1ro4XhSAAAAAABUAQGJsb2NraGFzaEBiaXRjb2luLm9yZzAw MDAwMDAwMDAwMDAwMDAwNDAyZmU2ZmI5YWQ2MTNjOTNlMTJiZGRmYzZlYzAyYTJi ZDkyZjAwMjA1MDU5NGQvFIAAAAAAFQARcGthLWFkZHJlc3NAZ251cGcub3JncGV0 ZUBwZXRlcnRvZC5vcmcACgkQwIXyHOf0udysLAgAgOoDv6G/qOzUHzaYPEvT4dYr okzbsLo7RrCCBlqD9OfavbB2SOexuU5ZcR2A9RSBP0XScPUNXAIQoe8fEQRB5mHK MPOhOpFFc8NzewJivQvI6pAx+9i444/DI6cUXsaSDqqYaP9Dal7pzSuLgO0Bjol2 mP7mO68anOZknuht/yiAMtKUPR5QjehOJQvGWkxKYdRDM5lWY9xP1oCWW/SKHJ0y iRbXrmMWBm7Zp58WM/LABINz8wI7lLbEBmR3FpYWr8sfozy2a9MDItg11Q0eXHgV FzKepK5ZRXyOMgLuQMankiHG4IKLvbqIfHk4NiOzZWqzrY2pNH2ZRuvQtix1RA== =5hyw -----END PGP SIGNATURE----- --dc+cDN39EJAMEtIO--