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-1.v29.ch3.sourceforge.com with esmtp (Exim 4.76) (envelope-from ) id 1XJQiK-0000RO-MM for bitcoin-development@lists.sourceforge.net; Mon, 18 Aug 2014 17:27:24 +0000 Received-SPF: pass (sog-mx-4.v43.ch3.sourceforge.com: domain of gmail.com designates 209.85.219.48 as permitted sender) client-ip=209.85.219.48; envelope-from=mh.in.england@gmail.com; helo=mail-oa0-f48.google.com; Received: from mail-oa0-f48.google.com ([209.85.219.48]) by sog-mx-4.v43.ch3.sourceforge.com with esmtps (TLSv1:RC4-SHA:128) (Exim 4.76) id 1XJQiJ-0007Th-PE for bitcoin-development@lists.sourceforge.net; Mon, 18 Aug 2014 17:27:24 +0000 Received: by mail-oa0-f48.google.com with SMTP id m1so4236811oag.7 for ; Mon, 18 Aug 2014 10:27:18 -0700 (PDT) MIME-Version: 1.0 X-Received: by 10.182.224.227 with SMTP id rf3mr4758408obc.70.1408382838297; Mon, 18 Aug 2014 10:27:18 -0700 (PDT) Sender: mh.in.england@gmail.com Received: by 10.76.97.132 with HTTP; Mon, 18 Aug 2014 10:27:18 -0700 (PDT) In-Reply-To: References: <20140818164543.GB31175@localhost.localdomain> Date: Mon, 18 Aug 2014 19:27:18 +0200 X-Google-Sender-Auth: lMBtC7mCj7UfrK2D7EJjKwonkVU Message-ID: From: Mike Hearn To: Gregory Maxwell Content-Type: multipart/alternative; boundary=089e013a05dec9515a0500eaae63 X-Spam-Score: -0.5 (/) 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 (mh.in.england[at]gmail.com) -0.0 SPF_PASS SPF: sender matches SPF record 1.0 HTML_MESSAGE BODY: HTML included in message 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: 1XJQiJ-0007Th-PE Cc: Ivan Pustogarov , Bitcoin Development Subject: Re: [Bitcoin-development] Outbound connections rotation 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: Mon, 18 Aug 2014 17:27:24 -0000 --089e013a05dec9515a0500eaae63 Content-Type: text/plain; charset=UTF-8 > > Connection rotation would be fine for improving a node's knoweldge > about available peers and making the network stronger against > partitioning. > It's also the first/next step towards decentralising the DNS seeds (for SPV clients), as it'd allow each node to explore the network and return better quality results in getaddr. > 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. > This is sort of what Tor is going through with their guard nodes and how often to rotate them. I think the attack Ivan is talking about does not require sybil attacks to work though, just listening to lots of peers. Raising the bar to require the attacker to receive lots of connections seems like a win. --089e013a05dec9515a0500eaae63 Content-Type: text/html; charset=UTF-8 Content-Transfer-Encoding: quoted-printable
Connection rotation would be fine for improving = a node's knoweldge
about available peers and making the network stronger against
partitioning.

It's also the first/n= ext step towards decentralising the DNS seeds (for SPV clients), as it'= d allow each node to explore the network and return better quality results = in getaddr.
=C2=A0
If you rotate where you sen= d out your transactions then with
very high probability a sybil pretending to be many nodes will observe
you transmitting directly.

This is sort= of what Tor is going through with their guard nodes and how often to rotat= e them.

I think the attack Ivan is talking about d= oes not require sybil attacks to work though, just listening to lots of pee= rs. Raising the bar to require the attacker to receive lots of connections = seems like a win.
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