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 2826A9F8 for ; Tue, 28 Jun 2016 20:36:13 +0000 (UTC) X-Greylist: from auto-whitelisted by SQLgrey-1.7.6 Received: from outmail148110.authsmtp.com (outmail148110.authsmtp.com [62.13.148.110]) by smtp1.linuxfoundation.org (Postfix) with ESMTP id 62D3A292 for ; Tue, 28 Jun 2016 20:36:12 +0000 (UTC) Received: from mail-c232.authsmtp.com (mail-c232.authsmtp.com [62.13.128.232]) by punt20.authsmtp.com (8.14.2/8.14.2/) with ESMTP id u5SKaAcA091742; Tue, 28 Jun 2016 21:36:10 +0100 (BST) Received: from petertodd.org (ec2-52-5-185-120.compute-1.amazonaws.com [52.5.185.120]) (authenticated bits=0) by mail.authsmtp.com (8.14.2/8.14.2/) with ESMTP id u5SKa7Bl054929 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=NO); Tue, 28 Jun 2016 21:36:08 +0100 (BST) Received: from [127.0.0.1] (localhost [127.0.0.1]) by petertodd.org (Postfix) with ESMTPSA id 2EB6B4015C; Tue, 28 Jun 2016 20:33:57 +0000 (UTC) Received: by localhost (Postfix, from userid 1000) id A32CB2056A; Tue, 28 Jun 2016 16:36:05 -0400 (EDT) Date: Tue, 28 Jun 2016 16:36:05 -0400 From: Peter Todd To: Eric Voskuil Message-ID: <20160628203605.GA1328@fedora-21-dvm> References: <87h9cecad5.fsf@rustcorp.com.au> <1E86A00F-0609-4DBC-9543-94AE04CC13C9@voskuil.org> <577234A4.3030808@jonasschnelli.ch> <360EF9B8-A174-41CA-AFDD-2BC2C0B4DECB@voskuil.org> <20160628182202.GA5519@fedora-21-dvm> <20160628201447.GA1148@fedora-21-dvm> <4DCF7DD2-6533-4F79-8CA1-871B67C01BDA@voskuil.org> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha256; protocol="application/pgp-signature"; boundary="sm4nu43k4a2Rpi4c" Content-Disposition: inline In-Reply-To: <4DCF7DD2-6533-4F79-8CA1-871B67C01BDA@voskuil.org> User-Agent: Mutt/1.5.23 (2014-03-12) X-Server-Quench: f1ebb6a4-3d6f-11e6-829e-00151795d556 X-AuthReport-Spam: If SPAM / abuse - report it at: http://www.authsmtp.com/abuse X-AuthRoute: OCd2Yg0TA1ZNQRgX IjsJECJaVQIpKltL GxAVKBZePFsRUQkR aQdMdAoUEkAaAgsB AmAbWVVeU1t7WWo7 bghPaBtcak9QXgdq T0pMXVMcUQALek0G dEIeVx17dQwIeX5w YUIsCHEODhZ8JEJg QRpSQ3AHZDJmdWgd WRVFdwNVdQJNdxoR b1V5GhFYa3VsNCMk FAgyOXU9MCtqYA50 eklUcAt6 X-Authentic-SMTP: 61633532353630.1037:706 X-AuthFastPath: 0 (Was 255) X-AuthSMTP-Origin: 52.5.185.120/25 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 Cc: Bitcoin Protocol Discussion Subject: Re: [bitcoin-dev] BIP 151 X-BeenThere: bitcoin-dev@lists.linuxfoundation.org X-Mailman-Version: 2.1.12 Precedence: list List-Id: Bitcoin Protocol Discussion List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Tue, 28 Jun 2016 20:36:13 -0000 --sm4nu43k4a2Rpi4c Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Tue, Jun 28, 2016 at 10:29:54PM +0200, Eric Voskuil wrote: >=20 >=20 > > On Jun 28, 2016, at 10:14 PM, Peter Todd wrote: > >=20 > >> On Tue, Jun 28, 2016 at 08:35:26PM +0200, Eric Voskuil wrote: > >> Hi Peter, > >>=20 > >> What in this BIP makes a MITM attack easier (or easy) to detect, or in= creases the probability of one being detected? > >=20 > > BIP151 gives users the tools to detect a MITM attack. > >=20 > > It's kinda like PGP in that way: lots of PGP users don't properly check= keys, >=20 > PGP requires a secure side channel for transmission of public keys. How d= oes one "check" a key of an anonymous peer? I know you well enough to know = you wouldn't trust a PGP key received over an insecure channel. >=20 > All you can prove is that you are talking to a peer and that communicatio= ns in the session remain with that peer. The peer can be the attacker. As J= onas has acknowledged, authentication is required to actually guard against= MITM attacks. Easy: anonymous peers aren't always actually anonymous. A MITM attacker can't easily distinguish communications between two nodes t= hat randomly picked their peers, and nodes that are connected because their operators manually used -addnode to peer; in the latter case the operators = can check whether or not they're being attacked with an out-of-band key check. --=20 https://petertodd.org 'peter'[:-1]@petertodd.org --sm4nu43k4a2Rpi4c Content-Type: application/pgp-signature; name="signature.asc" Content-Description: Digital signature -----BEGIN PGP SIGNATURE----- iQEcBAEBCAAGBQJXct+yAAoJEGOZARBE6K+y3xsH/Rj54dTZN0nFB2vU4CzonS00 Iljo9i0FXlo12qHcMgDRBnXu27Lh6wVuAlADf+gIPiGUKC8PUvGDxtqvIPTz7R+r lAoHvycHZ+PxVX4QdV8FCjzRlHRRV/2cHuhqemBBqGNx/rJskp59Ed2bnEur0wh3 CrU3Kd32h5aXBZA0FHcYSvL7GSig6GNqk3in8q6iYpC5Zs5djqm5kg5/3wWINNyF 9UVhJyjSbYTHk9ow3MRg4AKaxlB1Ksf2nWRrq+1J7U7v9ACjMjEttU30PmPugiFE rhYuS/q6wXgjvajrvCuiRirxVAUiFwRvsqrGWqNXZzYij1f4JgyR3JTFX/bo1QM= =t4hw -----END PGP SIGNATURE----- --sm4nu43k4a2Rpi4c--