From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from sog-mx-4.v43.ch3.sourceforge.com ([172.29.43.194] helo=mx.sourceforge.net) by sfs-ml-3.v29.ch3.sourceforge.com with esmtp (Exim 4.76) (envelope-from <pieter.wuille@gmail.com>) id 1XJQpm-0000bz-Nz for bitcoin-development@lists.sourceforge.net; Mon, 18 Aug 2014 17:35:06 +0000 Received-SPF: pass (sog-mx-4.v43.ch3.sourceforge.com: domain of gmail.com designates 209.85.213.181 as permitted sender) client-ip=209.85.213.181; envelope-from=pieter.wuille@gmail.com; helo=mail-ig0-f181.google.com; Received: from mail-ig0-f181.google.com ([209.85.213.181]) by sog-mx-4.v43.ch3.sourceforge.com with esmtps (TLSv1:RC4-SHA:128) (Exim 4.76) id 1XJQpl-0007hc-Oi for bitcoin-development@lists.sourceforge.net; Mon, 18 Aug 2014 17:35:06 +0000 Received: by mail-ig0-f181.google.com with SMTP id h3so8345731igd.14 for <bitcoin-development@lists.sourceforge.net>; Mon, 18 Aug 2014 10:35:00 -0700 (PDT) MIME-Version: 1.0 X-Received: by 10.50.234.193 with SMTP id ug1mr482997igc.20.1408383300385; Mon, 18 Aug 2014 10:35:00 -0700 (PDT) Received: by 10.50.156.135 with HTTP; Mon, 18 Aug 2014 10:35:00 -0700 (PDT) Received: by 10.50.156.135 with HTTP; Mon, 18 Aug 2014 10:35:00 -0700 (PDT) In-Reply-To: <CAAS2fgQZaDOtoh+_oaiZh6jMOacSuHbEM=vktBdThDP_7eRH0Q@mail.gmail.com> References: <20140818164543.GB31175@localhost.localdomain> <CAAS2fgQZaDOtoh+_oaiZh6jMOacSuHbEM=vktBdThDP_7eRH0Q@mail.gmail.com> Date: Mon, 18 Aug 2014 19:35:00 +0200 Message-ID: <CAPg+sBjQv7vrw63KbZf+mUj8W6h8GxdpE7xYbLLFfhm6-aGKdA@mail.gmail.com> From: Pieter Wuille <pieter.wuille@gmail.com> To: Gregory Maxwell <gmaxwell@gmail.com> Content-Type: multipart/alternative; boundary=001a113489e053e1940500eaca7d X-Spam-Score: -0.6 (/) X-Spam-Report: Spam Filtering performed by mx.sourceforge.net. See http://spamassassin.org/tag/ for more details. -1.5 SPF_CHECK_PASS SPF reports sender host as permitted sender for sender-domain 0.0 FREEMAIL_FROM Sender email is commonly abused enduser mail provider (pieter.wuille[at]gmail.com) -0.0 SPF_PASS SPF: sender matches SPF record 1.0 HTML_MESSAGE BODY: HTML included in message -0.1 DKIM_VALID_AU Message has a valid DKIM or DK signature from author's domain 0.1 DKIM_SIGNED Message has a DKIM or DK signature, not necessarily valid -0.1 DKIM_VALID Message has at least one valid DKIM or DK signature X-Headers-End: 1XJQpl-0007hc-Oi Cc: Ivan Pustogarov <ivan.pustogarov@uni.lu>, Bitcoin Dev <bitcoin-development@lists.sourceforge.net> Subject: Re: [Bitcoin-development] Outbound connections rotation X-BeenThere: bitcoin-development@lists.sourceforge.net X-Mailman-Version: 2.1.9 Precedence: list List-Id: <bitcoin-development.lists.sourceforge.net> List-Unsubscribe: <https://lists.sourceforge.net/lists/listinfo/bitcoin-development>, <mailto:bitcoin-development-request@lists.sourceforge.net?subject=unsubscribe> List-Archive: <http://sourceforge.net/mailarchive/forum.php?forum_name=bitcoin-development> List-Post: <mailto:bitcoin-development@lists.sourceforge.net> List-Help: <mailto:bitcoin-development-request@lists.sourceforge.net?subject=help> List-Subscribe: <https://lists.sourceforge.net/lists/listinfo/bitcoin-development>, <mailto:bitcoin-development-request@lists.sourceforge.net?subject=subscribe> X-List-Received-Date: Mon, 18 Aug 2014 17:35:07 -0000 --001a113489e053e1940500eaca7d Content-Type: text/plain; charset=ISO-8859-1 Yes, I believe peer rotation is useful, but not for privacy - just for improving the network's internal knowledge. I haven't looked at the implementation yet, but how I imagined it would be every X minutes you attempt a new outgoing connection, even if you're already at the outbound limit. Then, if a connection attempt succeeds, another connection (according to some scoring system) is replaced by it. Given such a mechanism, plus reasonable assurances that better connections survive for a longer time, I have no problem with rotating every few minutes. On Aug 18, 2014 7:23 PM, "Gregory Maxwell" <gmaxwell@gmail.com> wrote: > On Mon, Aug 18, 2014 at 9:46 AM, Ivan Pustogarov <ivan.pustogarov@uni.lu> > wrote: > > Hi there, > > I'd like to start a discussion on periodic rotation of outbound > connections. > > E.g. every 2-10 minutes an outbound connections is dropped and replaced > > by a new one. > > Connection rotation would be fine for improving a node's knoweldge > about available peers and making the network stronger against > partitioning. > > I haven't implemented this because I think your motivation is > _precisely_ opposite the behavior. If you keep a constant set of > outbound peers only those peers learn the origin of your transactions, > and so it is unlikely that any particular attacker will gain strong > evidence. If you rotate where you send out your transactions then with > very high probability a sybil pretending to be many nodes will observe > you transmitting directly. > > Ultimately, since the traffic is clear text, if you expect to have any > privacy at all in your broadcasts you should be broadcasting over tor > or i2p. > > > ------------------------------------------------------------------------------ > _______________________________________________ > Bitcoin-development mailing list > Bitcoin-development@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/bitcoin-development > --001a113489e053e1940500eaca7d Content-Type: text/html; charset=ISO-8859-1 Content-Transfer-Encoding: quoted-printable <p dir=3D"ltr">Yes, I believe peer rotation is useful, but not for privacy = - just for improving the network's internal knowledge.</p> <p dir=3D"ltr">I haven't looked at the implementation yet, but how I im= agined it would be every X minutes you attempt a new outgoing connection, e= ven if you're already at the outbound limit. Then, if a connection atte= mpt succeeds, another connection (according to some scoring system) is repl= aced by it. Given such a mechanism, plus reasonable assurances that better = connections survive for a longer time, I have no problem with rotating ever= y few minutes.<br> </p> <div class=3D"gmail_quote">On Aug 18, 2014 7:23 PM, "Gregory Maxwell&q= uot; <<a href=3D"mailto:gmaxwell@gmail.com">gmaxwell@gmail.com</a>> w= rote:<br type=3D"attribution"><blockquote class=3D"gmail_quote" style=3D"ma= rgin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"> On Mon, Aug 18, 2014 at 9:46 AM, Ivan Pustogarov <<a href=3D"mailto:ivan= .pustogarov@uni.lu">ivan.pustogarov@uni.lu</a>> wrote:<br> > Hi there,<br> > I'd like to start a discussion on periodic rotation of outbound co= nnections.<br> > E.g. every 2-10 minutes an outbound connections is dropped and replace= d<br> > by a new one.<br> <br> Connection rotation would be fine for improving a node's knoweldge<br> about available peers and making the network stronger against<br> partitioning.<br> <br> I haven't implemented this because I think your motivation is<br> _precisely_ opposite the behavior. If you keep a constant set of<br> outbound peers only those peers learn the origin of your transactions,<br> and so it is unlikely that any particular attacker will gain strong<br> evidence. If you rotate where you send out your transactions then with<br> very high probability a sybil pretending to be many nodes will observe<br> you transmitting directly.<br> <br> Ultimately, since the traffic is clear text, if you expect to have any<br> privacy at all in your broadcasts you should be broadcasting over tor<br> or i2p.<br> <br> ---------------------------------------------------------------------------= ---<br> _______________________________________________<br> Bitcoin-development mailing list<br> <a href=3D"mailto:Bitcoin-development@lists.sourceforge.net">Bitcoin-develo= pment@lists.sourceforge.net</a><br> <a href=3D"https://lists.sourceforge.net/lists/listinfo/bitcoin-development= " target=3D"_blank">https://lists.sourceforge.net/lists/listinfo/bitcoin-de= velopment</a><br> </blockquote></div> --001a113489e053e1940500eaca7d--