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 247BB721 for ; Tue, 28 Jun 2016 18:22:12 +0000 (UTC) X-Greylist: from auto-whitelisted by SQLgrey-1.7.6 Received: from outmail148154.authsmtp.co.uk (outmail148154.authsmtp.co.uk [62.13.148.154]) by smtp1.linuxfoundation.org (Postfix) with ESMTP id CAFAA12D for ; Tue, 28 Jun 2016 18:22:10 +0000 (UTC) Received: from mail-c232.authsmtp.com (mail-c232.authsmtp.com [62.13.128.232]) by punt24.authsmtp.com (8.14.2/8.14.2/) with ESMTP id u5SIM822052688; Tue, 28 Jun 2016 19:22:08 +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 u5SIM4rh024914 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=NO); Tue, 28 Jun 2016 19:22:05 +0100 (BST) Received: from [127.0.0.1] (localhost [127.0.0.1]) by petertodd.org (Postfix) with ESMTPSA id 71D124011D; Tue, 28 Jun 2016 18:19:54 +0000 (UTC) Received: by localhost (Postfix, from userid 1000) id F3D852036D; Tue, 28 Jun 2016 14:22:02 -0400 (EDT) Date: Tue, 28 Jun 2016 14:22:02 -0400 From: Peter Todd To: Eric Voskuil , Bitcoin Protocol Discussion Message-ID: <20160628182202.GA5519@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> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha256; protocol="application/pgp-signature"; boundary="vkogqOf2sHV7VnPd" Content-Disposition: inline In-Reply-To: <360EF9B8-A174-41CA-AFDD-2BC2C0B4DECB@voskuil.org> User-Agent: Mutt/1.5.23 (2014-03-12) X-Server-Quench: 37d32568-3d5d-11e6-829e-00151795d556 X-AuthReport-Spam: If SPAM / abuse - report it at: http://www.authsmtp.com/abuse X-AuthRoute: OCd2Yg0TA1ZNQRgX IjsJECJaVQIpKltL GxAVKBZePFsRUQkR aQdMdAoUEkAaAgsB AmAbWl1eUl97WWY7 bghPaBtcak9QXgdq T0pMXVMcUQALeGEF REYeUB17dgEIeX5x YE4sXXcPX0Z/c05g QRpRQXAHZDJmdWgd 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 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 18:22:12 -0000 --vkogqOf2sHV7VnPd Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Tue, Jun 28, 2016 at 06:45:58PM +0200, Eric Voskuil via bitcoin-dev wrot= e: > > 1) Transaction censorship > > ISPs, WIFI provider or any other MITM, can holdback/censor unconfirmed > > transactions. Regardless if you are a miner or a validation/wallet node. > >=20 > > 2) Peer censorship > > MITM can remove or add entries from a "addr" message. > >=20 > > 3) Fingerprinting > > ISPs or any other MITM can intercept/inject fingerprinting relevant > > messages like "mempool" to analyze the bitcoin network. >=20 > Encryption alone cannot protect against a MITM attack in an anonymous and= permissionless network. This is accepted in the BIP (and your follow-up re= ply). Being able to easily detect MITM attacks is a _huge_ step forward that shouldn't be underestimated; even if 99% of users aren't in a position to detect the MITM you only need a small subset of users that do the necessary checks to alert the wider community, who can then respond with stronger security measures. Those measures are likely to be more costly - authentica= ted systems are significantly harder than not - so better to save your efforts until the need for them is more obvious. Also the fact that an attack has a reasonable probability of detection is a= big disincentive for many types of attackers - note how one of the things revea= led in the Snowden leaks was the fact that the NSA generally tries quite hard to avoid tipping off targets to the fact that they're being surveilled, with a myriad of carefully scripted policies to control when and how exploits are = used against targets. --=20 https://petertodd.org 'peter'[:-1]@petertodd.org --vkogqOf2sHV7VnPd Content-Type: application/pgp-signature; name="signature.asc" Content-Description: Digital signature -----BEGIN PGP SIGNATURE----- iQEcBAEBCAAGBQJXcsBIAAoJEGOZARBE6K+yxCAH/2um4RHuNo0/GxMrhxJ/3XLb tqAxwtX1YDZNzBJtzkxm2z4LFtvIMtZOuNaS4mEt0KzAaderI46G+ocsX1q3kOi+ zUNMoJc+ga0BF4xkmilgM3YbbSMtHpAupb2VwrSGhR1dT3fvf8l6aE093j1ny6pT OZYb8GUUFHMPp3jscxH6BRBo+3OR0vEPbjEgDMPh+MYrGDCObTG9acC6S6uhbH0A wgZBOGINyjdH3MUDevKkHQJT8oXLme4EsL5zp5JIJmuxEmC7jrV+a+um6wRKU0vO UOpmBJjpbUffjw6NxpLAwgXIs8+q24QTqqKnu73TlOH0LlMyT7OZ8D4aS3iYi7Y= =RCLU -----END PGP SIGNATURE----- --vkogqOf2sHV7VnPd--