From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from sog-mx-3.v43.ch3.sourceforge.com ([172.29.43.193] helo=mx.sourceforge.net) by sfs-ml-4.v29.ch3.sourceforge.com with esmtp (Exim 4.76) (envelope-from ) id 1YQxIR-0000NC-5p for bitcoin-development@lists.sourceforge.net; Thu, 26 Feb 2015 12:12:03 +0000 Received-SPF: pass (sog-mx-3.v43.ch3.sourceforge.com: domain of m.gmane.org designates 80.91.229.3 as permitted sender) client-ip=80.91.229.3; envelope-from=gcbd-bitcoin-development@m.gmane.org; helo=plane.gmane.org; Received: from plane.gmane.org ([80.91.229.3]) by sog-mx-3.v43.ch3.sourceforge.com with esmtps (TLSv1:AES256-SHA:256) (Exim 4.76) id 1YQxIP-0005j8-R5 for bitcoin-development@lists.sourceforge.net; Thu, 26 Feb 2015 12:12:03 +0000 Received: from list by plane.gmane.org with local (Exim 4.69) (envelope-from ) id 1YQxII-00078o-Ob for bitcoin-development@lists.sourceforge.net; Thu, 26 Feb 2015 13:11:54 +0100 Received: from f052018132.adsl.alicedsl.de ([78.52.18.132]) by main.gmane.org with esmtp (Gmexim 0.1 (Debian)) id 1AlnuQ-0007hv-00 for ; Thu, 26 Feb 2015 13:11:54 +0100 Received: from andreas by f052018132.adsl.alicedsl.de with local (Gmexim 0.1 (Debian)) id 1AlnuQ-0007hv-00 for ; Thu, 26 Feb 2015 13:11:54 +0100 X-Injected-Via-Gmane: http://gmane.org/ To: bitcoin-development@lists.sourceforge.net From: Andreas Schildbach Date: Thu, 26 Feb 2015 13:11:48 +0100 Message-ID: <54EF0D84.5070301@schildbach.de> References: <771EF431-6644-4BE4-B39C-CA73CFC18DB4@gmail.com> <54EEE81F.1000602@schildbach.de> <54EEF12B.2050803@schildbach.de> Mime-Version: 1.0 Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: 8bit X-Complaints-To: usenet@ger.gmane.org X-Gmane-NNTP-Posting-Host: f052018132.adsl.alicedsl.de User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:31.0) Gecko/20100101 Thunderbird/31.4.0 In-Reply-To: X-Spam-Score: -0.4 (/) 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_HELO_PASS SPF: HELO matches SPF record 1.1 DKIM_ADSP_ALL No valid author signature, domain signs all mail -0.0 T_RP_MATCHES_RCVD Envelope sender domain matches handover relay domain -0.0 SPF_PASS SPF: sender matches SPF record 0.0 AWL AWL: Adjusted score from AWL reputation of From: address X-Headers-End: 1YQxIP-0005j8-R5 Subject: Re: [Bitcoin-development] Providing Payment Request within URI 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: Thu, 26 Feb 2015 12:12:03 -0000 On 02/26/2015 12:14 PM, Oleg Andreev wrote: > >> Base43 is the same as any BaseX standard, but using a different alphabet >> (43 characters). It's meant to be used for efficiently storing binary >> data into QR codes. The alphabet is picked to match the 'Alphanumeric' >> input mode of QR codes as closely as possible, but at the same time be >> allowed in URIs. > > Does it mean Base58 or Base64 take more space in QR code than Base43? Do you have an estimate of the gains? Both Base58 and Base64 force QR codes into binary encoding. Base64 can take 6 bits per char, binary of course has 8 bits per char. So you're wasting 25% of space if you use Base64, a little bit more with Base58. Base43 takes log2(43) = 5.43 bits per char, while each char uses up 5.5 bits in QR codes in 'Alphanumeric' encoding. So that's a waste of 1.3%. Source for QR code standard: http://en.wikipedia.org/wiki/QR_code