Re: [Bitcoin-development] Bitcoin at POS using BIP70, NFC and offline payments - implementer feedback
On 02/23/2015 04:09 PM, Jan Vornberger wrote: I'm still concerned that the fact, that Bluetooth is often disabled, is a problem for the UX. And it's not just a one-time thing as with NFC, which is - in my experience - also often disabled, but then people turn it on and leave it on. It's the same with Bluetooth. More and more people use audio via Bluetooth, mostly because they use a headset or stream their music to their stereo at home. Those that still switch off Bluetooth all the time can simply press a button. It can't be any easier. Another idea could be to request the permission BLUETOOTH_ADMIN which, as far as I know, allows you to programmatically turn on Bluetooth without user interaction. True, but those people who switch off Bluetooth will also simply not install the app because of that permission. If only Android had optional permissions... )-: -- Dive into the World of Parallel Programming The Go Parallel Website, sponsored by Intel and developed in partnership with Slashdot Media, is your hub for all things parallel software development, from weekly thought leadership blogs to news, videos, case studies, tutorials and more. Take a look and join the conversation now. http://goparallel.sourceforge.net/ ___ Bitcoin-development mailing list Bitcoin-development@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/bitcoin-development
Re: [Bitcoin-development] Providing Payment Request within URI
Yeah, you'd be limited to simple usecases. X509 signing or lots of outputs will make the QR code hard to scan. However, if all you want to do is send to a custom script (without using P2SH) I invite you to have a look at https://github.com/schildbach/bitcoin-wallet/blob/master/wallet/src/de/schildbach/wallet/ui/InputParser.java#L86 https://github.com/schildbach/bitcoin-wallet/blob/master/wallet/src/de/schildbach/wallet/util/Qr.java#L134 https://github.com/schildbach/bitcoin-wallet/blob/master/wallet/src/de/schildbach/wallet/util/Base43.java Basically it's BITCOIN:- plus the payment request in Base43 encoded form. I picked Base43, because that's optimized for QR codes. On 02/24/2015 04:58 PM, Oleg Andreev wrote: Hi, I wonder if there is a standard way to put Payment Request data into bitcoin: URI or directly into QR code. The goal is to allow device to generate a multi-output payment request on its own, without relying on the server and x509 certificates. When scanned via QR code from, say, POS, it's pretty secure, so no additional authentication needed. I'd like something like this: bitcoin:?r=data://base64url-encoded-payment-request If there's no standard for that, would it be a good idea to extend BIP72 this way? -- Dive into the World of Parallel Programming The Go Parallel Website, sponsored by Intel and developed in partnership with Slashdot Media, is your hub for all things parallel software development, from weekly thought leadership blogs to news, videos, case studies, tutorials and more. Take a look and join the conversation now. http://goparallel.sourceforge.net/ -- Dive into the World of Parallel Programming The Go Parallel Website, sponsored by Intel and developed in partnership with Slashdot Media, is your hub for all things parallel software development, from weekly thought leadership blogs to news, videos, case studies, tutorials and more. Take a look and join the conversation now. http://goparallel.sourceforge.net/ ___ Bitcoin-development mailing list Bitcoin-development@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/bitcoin-development
Re: [Bitcoin-development] Providing Payment Request within URI
Thanks for references. Yeah, I don't need X509 signing (if I could use certificates, I wouldn't need to include PR in the URL in the first place). I presume you used BITCOIN:-payment request instead of bitcoin:?r=somescheme://payment request to make it more compact. I also tried to look up Base43, but I could not find any info on how it is specifically optimized for QR codes. Could you enlighten me? On 26 Feb 2015, at 10:32, Andreas Schildbach andr...@schildbach.de wrote: Yeah, you'd be limited to simple usecases. X509 signing or lots of outputs will make the QR code hard to scan. However, if all you want to do is send to a custom script (without using P2SH) I invite you to have a look at https://github.com/schildbach/bitcoin-wallet/blob/master/wallet/src/de/schildbach/wallet/ui/InputParser.java#L86 https://github.com/schildbach/bitcoin-wallet/blob/master/wallet/src/de/schildbach/wallet/util/Qr.java#L134 https://github.com/schildbach/bitcoin-wallet/blob/master/wallet/src/de/schildbach/wallet/util/Base43.java Basically it's BITCOIN:- plus the payment request in Base43 encoded form. I picked Base43, because that's optimized for QR codes. On 02/24/2015 04:58 PM, Oleg Andreev wrote: Hi, I wonder if there is a standard way to put Payment Request data into bitcoin: URI or directly into QR code. The goal is to allow device to generate a multi-output payment request on its own, without relying on the server and x509 certificates. When scanned via QR code from, say, POS, it's pretty secure, so no additional authentication needed. I'd like something like this: bitcoin:?r=data://base64url-encoded-payment-request If there's no standard for that, would it be a good idea to extend BIP72 this way? -- Dive into the World of Parallel Programming The Go Parallel Website, sponsored by Intel and developed in partnership with Slashdot Media, is your hub for all things parallel software development, from weekly thought leadership blogs to news, videos, case studies, tutorials and more. Take a look and join the conversation now. http://goparallel.sourceforge.net/ -- Dive into the World of Parallel Programming The Go Parallel Website, sponsored by Intel and developed in partnership with Slashdot Media, is your hub for all things parallel software development, from weekly thought leadership blogs to news, videos, case studies, tutorials and more. Take a look and join the conversation now. http://goparallel.sourceforge.net/ ___ Bitcoin-development mailing list Bitcoin-development@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/bitcoin-development
Re: [Bitcoin-development] Providing Payment Request within URI
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? -- Dive into the World of Parallel Programming The Go Parallel Website, sponsored by Intel and developed in partnership with Slashdot Media, is your hub for all things parallel software development, from weekly thought leadership blogs to news, videos, case studies, tutorials and more. Take a look and join the conversation now. http://goparallel.sourceforge.net/ ___ Bitcoin-development mailing list Bitcoin-development@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/bitcoin-development
Re: [Bitcoin-development] Providing Payment Request within URI
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 -- Dive into the World of Parallel Programming The Go Parallel Website, sponsored by Intel and developed in partnership with Slashdot Media, is your hub for all things parallel software development, from weekly thought leadership blogs to news, videos, case studies, tutorials and more. Take a look and join the conversation now. http://goparallel.sourceforge.net/ ___ Bitcoin-development mailing list Bitcoin-development@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/bitcoin-development
Re: [Bitcoin-development] Bitcoin at POS using BIP70, NFC and offline payments - implementer feedback
On 02/24/2015 11:41 AM, Mike Hearn wrote: Does this not also require the BT publication of the script for a P2SH address? You mean if the URI you're serving is like this? bitcoin:3aBcD?bt= Yes it would. I guess then, the server would indicate both the script, and the key within that script that it wanted to use. A bit more complex but would still work to save URI space. What if the script doesn't use any key at all? Somehow this re-using the fallback address idea feels less and less appealing to me. I think we should add our own parameter and let go of fallback addresses as soon as possible. If will waste space during the transition period, but after that it should make no difference any more. -- Dive into the World of Parallel Programming The Go Parallel Website, sponsored by Intel and developed in partnership with Slashdot Media, is your hub for all things parallel software development, from weekly thought leadership blogs to news, videos, case studies, tutorials and more. Take a look and join the conversation now. http://goparallel.sourceforge.net/ ___ Bitcoin-development mailing list Bitcoin-development@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/bitcoin-development
