Received: from sog-mx-2.v43.ch3.sourceforge.com ([172.29.43.192] helo=mx.sourceforge.net) by sfs-ml-4.v29.ch3.sourceforge.com with esmtp (Exim 4.76) (envelope-from ) id 1UmPJi-0005hR-E6 for bitcoin-development@lists.sourceforge.net; Tue, 11 Jun 2013 14:12:58 +0000 Received-SPF: pass (sog-mx-2.v43.ch3.sourceforge.com: domain of gmail.com designates 209.85.223.172 as permitted sender) client-ip=209.85.223.172; envelope-from=pieter.wuille@gmail.com; helo=mail-ie0-f172.google.com; Received: from mail-ie0-f172.google.com ([209.85.223.172]) by sog-mx-2.v43.ch3.sourceforge.com with esmtps (TLSv1:RC4-SHA:128) (Exim 4.76) id 1UmPJh-0003LY-HB for bitcoin-development@lists.sourceforge.net; Tue, 11 Jun 2013 14:12:58 +0000 Received: by mail-ie0-f172.google.com with SMTP id 17so19809230iea.17 for ; Tue, 11 Jun 2013 07:12:52 -0700 (PDT) MIME-Version: 1.0 X-Received: by 10.50.41.34 with SMTP id c2mr997910igl.57.1370959972228; Tue, 11 Jun 2013 07:12:52 -0700 (PDT) Received: by 10.50.149.233 with HTTP; Tue, 11 Jun 2013 07:12:52 -0700 (PDT) In-Reply-To: References: Date: Tue, 11 Jun 2013 16:12:52 +0200 Message-ID: From: Pieter Wuille To: Melvin Carvalho Content-Type: text/plain; charset=ISO-8859-1 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 FREEMAIL_FROM Sender email is commonly abused enduser mail provider (pieter.wuille[at]gmail.com) -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: 1UmPJh-0003LY-HB Cc: Bitcoin Dev Subject: Re: [Bitcoin-development] Bitcoin addresses -- opaque or not 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: Tue, 11 Jun 2013 14:12:58 -0000 On Tue, Jun 11, 2013 at 3:11 PM, Melvin Carvalho wrote: > There was some confusion on IRC as to whether bitcoin addresses are opaque > or not. > > https://en.bitcoin.it/wiki/Address > > For the sake of argument let's say that opaque means that you can tell > nothing about the address by examining the characters. > > My understanding was that they are NOT opaque, and that if that has changed, > it will invalidate much at least some wiki page, for examples at least some > of the following would now be false: I'm afraid this is the result of a misunderstanding. Yesterday on IRC you were asking why the URI specification doesn't include the semantics and encoding of addresses. Some people, including me, argued that addresses should be considered opaque. That doesn't mean they don't have well-specified definition, only that for the purposes of URI parsing and handling, code shouldn't know or care what they represent or how they are formatted. Addresses are specified in one place, and the URI format simply passes addresses through. The reason for keeping them independent is that the address format could change (say, a new type is added, like P2SH (BIP13) before), and there is no reason why this should break or even concern URI handling code. Clearly, anything that actually interprets addresses in order to construct transactions will need changing. It's just two separate concerns, and they should be dealt with separately. -- Pieter