Received: from sog-mx-2.v43.ch3.sourceforge.com ([172.29.43.192] helo=mx.sourceforge.net) by sfs-ml-3.v29.ch3.sourceforge.com with esmtp (Exim 4.76) (envelope-from ) id 1XJtfC-0000RJ-3h for bitcoin-development@lists.sourceforge.net; Wed, 20 Aug 2014 00:22:06 +0000 Received-SPF: pass (sog-mx-2.v43.ch3.sourceforge.com: domain of bitpay.com designates 209.85.213.49 as permitted sender) client-ip=209.85.213.49; envelope-from=jgarzik@bitpay.com; helo=mail-yh0-f49.google.com; Received: from mail-yh0-f49.google.com ([209.85.213.49]) by sog-mx-2.v43.ch3.sourceforge.com with esmtps (TLSv1:RC4-SHA:128) (Exim 4.76) id 1XJtfB-0004W3-7m for bitcoin-development@lists.sourceforge.net; Wed, 20 Aug 2014 00:22:06 +0000 Received: by mail-yh0-f49.google.com with SMTP id b6so6339250yha.8 for ; Tue, 19 Aug 2014 17:21:55 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20130820; h=x-gm-message-state:mime-version:in-reply-to:references:from:date :message-id:subject:to:cc:content-type; bh=aC5BBWFOsX5iXiN7IQDsPBoCRcQwNbXeqfZSkUVLKMg=; b=Wb0IiROaZRatJkZlRFxRV2Vq7VBMMDzo9TkIfFIA+Y+A08YHFnjGzluwCdB0s1PcAU Vxjq5WYGG/BJYjqsogiBmqhcTaDTdJMNx8N7r+DW5xG/2WJP63M3F6lEjukHHXGSA8le 1zm2IgHzkWAOx/4GuP33IxT3LHjlbHds8TqeQsAWNIW9N4oVtKZatYgSuC/ds8Hpkcqm qHbi0YYwc8eL9TKpzIWKJIiDfVyZbO2czZjCFI/rQVOu0+SHXnUH3WGKKw7dVrM2LOQo 5i/x+sMvIU8xHSMMil0/SvynN9IMP2xndNJ7J6YKsS8H1wiqVex9gPnmCyRSlfILUCkN r9Cg== X-Gm-Message-State: ALoCoQnBDK1TQ9bSYdRWtPYUPk/+ETLPGkZrC3uMEMzWDDr6c8q8l+GVlIQaIQpFm/gcBVoNJy7B X-Received: by 10.236.149.76 with SMTP id w52mr49488453yhj.93.1408494115546; Tue, 19 Aug 2014 17:21:55 -0700 (PDT) MIME-Version: 1.0 Received: by 10.170.37.200 with HTTP; Tue, 19 Aug 2014 17:21:35 -0700 (PDT) In-Reply-To: <3476b0a1-e08a-46bf-9ee4-ef56fcb02d72@email.android.com> References: <0C0EF7F9-DBBA-4872-897D-63CFA3853726@ricmoo.com> <33D4B2E3-DBF0-444E-B76A-765C4C17E964@ricmoo.com> <53F37635.5070807@riseup.net> <53F38AC9.4000608@corganlabs.com> <53F3DFF7.9070709@jrn.me.uk> <3476b0a1-e08a-46bf-9ee4-ef56fcb02d72@email.android.com> From: Jeff Garzik Date: Tue, 19 Aug 2014 20:21:35 -0400 Message-ID: To: Peter Todd Content-Type: text/plain; charset=UTF-8 X-Spam-Score: -1.6 (-) 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 SPF_PASS SPF: sender matches SPF record -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: 1XJtfB-0004W3-7m Cc: Bitcoin Development , Justus Ranvier Subject: Re: [Bitcoin-development] Proposal: Encrypt bitcoin messages 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: Wed, 20 Aug 2014 00:22:06 -0000 On Tue, Aug 19, 2014 at 8:16 PM, Peter Todd wrote: > On 19 August 2014 19:40:39 GMT-04:00, Jeff Garzik wrote: >>Encryption is of little value if you may deduce the same information >>by observing packet sizes and timings. > > That is simply incorrect. The resources required to do that kind of monitoring are very high; even the NSA can't pull it off consistently for Hardly. For example, when a new block arrives on the network, a single observer at a single location may obtain a binary "likely|not bitcoin protocol" decision from a spike in usage correlated with sudden, global network activity after a period of inactivity. I'll not detail all such metrics. -- Jeff Garzik Bitcoin core developer and open source evangelist BitPay, Inc. https://bitpay.com/