Re: [Bitcoin-development] Paper Currency
Practically I would approach it from a different angle. We need to make sure that notes we're accepting are still loaded, but assuming it's NFC enabled this is still quite easy for the user and is an acceptable usability drawback. Then what we need to make sure is that when someone is redeeming the notes - he has control over physical object itself, ideally for a period of time. With some active powered electronics in place it would be easy, but how do we do it without anything active in place? Best regards, Alex Kotenko 2014-05-18 21:10 GMT+01:00 Natanael natanae...@gmail.com: The problem with not involving any electronics is that somebody needs to generate a recoverable private key that we have to trust haven't recovered the private key. The only plausible solution is multisignature P2SH addresses where you trust several independent entities to not collude instead, where you combine their paper notes into one piece. And then you still don't know if all the private keys are recoverable to you (failed print?). - Sent from my phone Den 18 maj 2014 20:48 skrev Alex Kotenko alexy...@gmail.com: Erm, few things here. - I can't see really how to embed electronics capable to run an SPV client into printed paper. I know that passive NFC tags can be printed on paper, but not actual chips and/or power modules. So we are talking about a completely different things here. - even with paper notes printed proprietarily by some business the notes itself still can have routes for independent blockchain-based verification, and you won't need to trust anybody to test it. You will have to trust security of the notes itself, but this is same as when you trust the phone manufacturer when you're putting your bitcoin wallet on it. So really I see only issues of technical security in here, and this is the problem I'm seeking solutions for. Best regards, Alex Kotenko 2014-05-18 14:50 GMT+01:00 Natanael natanae...@gmail.com: Now you are talking about Trusted Platform Modules. Like smartcards, actually. Devices that won't leak their keys but let the holder spend the coins. It could even have it's own simple SPV wallet client to make it easier to handle. And they'd use the attestation features provided by the TPM to prove the software it's unmodified top the current holder. But then you still have to trust the manufacturer of the device, and you have to trust it has no exploitable side channels. - Sent from my phone Den 18 maj 2014 13:52 skrev Alex Kotenko alexy...@gmail.com: -- Accelerate Dev Cycles with Automated Cross-Browser Testing - For FREE Instantly run your Selenium tests across 300+ browser/OS combos. Get unparalleled scalability from the best Selenium testing platform available Simple to use. Nothing to install. Get started now for free. http://p.sf.net/sfu/SauceLabs___ Bitcoin-development mailing list Bitcoin-development@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/bitcoin-development
Re: [Bitcoin-development] Paper Currency
Submitted with humility and some fear of getting laughed out of here... Off topic aside, a bunch of us have lately started to think about the atmosphere on this list and how to improve it. Nobody should have to fear getting flamed or laughed at for proposing ideas, even if they turn out to be silly ones. Gavin talked about this in his Bitcoin 2014 keynote and asked for someone to solve the forum trolling problem. I don't know if there are any silver bullets per se, but: 1) Please do keep ideas coming. It's easy to mute threads in any good mail client for people who don't care. If anyone gets too aggressive, the rest of us will remind them that this is unacceptable. 2) If you're willing to become a list moderator, please get in touch. Gavin and I are looking for neutral people who are willing to keep up with this list and help ensure the debate is civilised. Ideally moderation is not necessary, but that's what we tried so far and we keep getting consistent feedback from lots of people that it's not working. -- Accelerate Dev Cycles with Automated Cross-Browser Testing - For FREE Instantly run your Selenium tests across 300+ browser/OS combos. Get unparalleled scalability from the best Selenium testing platform available Simple to use. Nothing to install. Get started now for free. http://p.sf.net/sfu/SauceLabs___ Bitcoin-development mailing list Bitcoin-development@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/bitcoin-development
Re: [Bitcoin-development] Paper Currency
Alex, I think that what you are talking about more or less something like the Firmcoin Check: http://firmcoin.com/?p=92 On 18/05/2014 08:47 a.m., Alex Kotenko wrote: One problem we couldn't figure out here though - how to protect the notes from unauthorized redeem. Like if someone else tries to reach your wallet with his own NFC - how can we distinguish between deliberate redeem by owner and fraudulent redeem by anybody else with custom built long range NFC antenna? Any ideas? The firmcoin has two capacitive buttons that you have to press in sequence to redeem to coins. No long range antenna can do that. Best regards, Sergio. PS: the device has patents pending -- Accelerate Dev Cycles with Automated Cross-Browser Testing - For FREE Instantly run your Selenium tests across 300+ browser/OS combos. Get unparalleled scalability from the best Selenium testing platform available Simple to use. Nothing to install. Get started now for free. http://p.sf.net/sfu/SauceLabs___ Bitcoin-development mailing list Bitcoin-development@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/bitcoin-development
Re: [Bitcoin-development] Paper Currency
2014-05-18 13:14 GMT+01:00 Andreas Schildbach andr...@schildbach.de: One problem we couldn't figure out here though - how to protect the notes from unauthorized redeem. Like if someone else tries to reach your wallet with his own NFC - how can we distinguish between deliberate redeem by owner and fraudulent redeem by anybody else with custom built long range NFC antenna? Any ideas? I think you'd need multiple factors to protect against that attack. Like encrypting with a key that is printed on the note as an QR code. On Sun, May 18, 2014 at 7:51 AM, Alex Kotenko alexy...@gmail.com wrote: Yes, but it must not sacrifice usability. It's paper money, people are used to it and they have rather high standard of expectations in this area. Any usbility sacrifices in this area result into failure of the whole thing. Best regards, Alex Kotenko One thought I had reading through this exchange: I think the general public is becoming more aware of the hacker with a long range antenna sort of attack, since credit cards are getting microchips that can be scanned. There's a few videos I've seen of white hat hackers demonstrating how a suitcase-sized apparatus carried by someone walking down the street can scan and make charges on cards in people's pockets as the attacker brushes past. Hence RFID-blocking sleeves/wallets are on the market, such that your smart credit card can't make a purchase while its in your wallet. Is a RFID-blocking wallet also NFC-blocking? Irregardless of whatever future cash you choose to carry (be it credit card or bitcoin card/coin/cash), perhaps its the wallet/purse that needs an upgrade, to ensure your money doesn't spend itself while its in your pocket, but you can easily remove it and spend it conveniently? Brooks -- Accelerate Dev Cycles with Automated Cross-Browser Testing - For FREE Instantly run your Selenium tests across 300+ browser/OS combos. Get unparalleled scalability from the best Selenium testing platform available Simple to use. Nothing to install. Get started now for free. http://p.sf.net/sfu/SauceLabs ___ Bitcoin-development mailing list Bitcoin-development@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/bitcoin-development
Re: [Bitcoin-development] Paper Currency
Asking random ignorant stranger to care to protect themselves never works. We need solution that requires strictly zero effort. Best regards, Alex Kotenko 2014-05-19 14:06 GMT+01:00 Brooks Boyd bo...@midnightdesign.ws: 2014-05-18 13:14 GMT+01:00 Andreas Schildbach andr...@schildbach.de: One problem we couldn't figure out here though - how to protect the notes from unauthorized redeem. Like if someone else tries to reach your wallet with his own NFC - how can we distinguish between deliberate redeem by owner and fraudulent redeem by anybody else with custom built long range NFC antenna? Any ideas? I think you'd need multiple factors to protect against that attack. Like encrypting with a key that is printed on the note as an QR code. On Sun, May 18, 2014 at 7:51 AM, Alex Kotenko alexy...@gmail.com wrote: Yes, but it must not sacrifice usability. It's paper money, people are used to it and they have rather high standard of expectations in this area. Any usbility sacrifices in this area result into failure of the whole thing. Best regards, Alex Kotenko One thought I had reading through this exchange: I think the general public is becoming more aware of the hacker with a long range antenna sort of attack, since credit cards are getting microchips that can be scanned. There's a few videos I've seen of white hat hackers demonstrating how a suitcase-sized apparatus carried by someone walking down the street can scan and make charges on cards in people's pockets as the attacker brushes past. Hence RFID-blocking sleeves/wallets are on the market, such that your smart credit card can't make a purchase while its in your wallet. Is a RFID-blocking wallet also NFC-blocking? Irregardless of whatever future cash you choose to carry (be it credit card or bitcoin card/coin/cash), perhaps its the wallet/purse that needs an upgrade, to ensure your money doesn't spend itself while its in your pocket, but you can easily remove it and spend it conveniently? Brooks -- Accelerate Dev Cycles with Automated Cross-Browser Testing - For FREE Instantly run your Selenium tests across 300+ browser/OS combos. Get unparalleled scalability from the best Selenium testing platform available Simple to use. Nothing to install. Get started now for free. http://p.sf.net/sfu/SauceLabs ___ Bitcoin-development mailing list Bitcoin-development@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/bitcoin-development -- Accelerate Dev Cycles with Automated Cross-Browser Testing - For FREE Instantly run your Selenium tests across 300+ browser/OS combos. Get unparalleled scalability from the best Selenium testing platform available Simple to use. Nothing to install. Get started now for free. http://p.sf.net/sfu/SauceLabs___ Bitcoin-development mailing list Bitcoin-development@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/bitcoin-development
Re: [Bitcoin-development] Paper Currency
Alex, I think the problem of making paper bitcoins is equivalent to the idea of creating paper implementation of bitcoin sidechain. Hard one in my mind. If we could resolve this one in secure and decentralized way it would be the same breakthrough as bitcoin itself is. Martin Sip On 18/05/2014 08:47 a.m., Alex Kotenko wrote: One problem we couldn't figure out here though - how to protect the notes from unauthorized redeem. Like if someone else tries to reach your wallet with his own NFC - how can we distinguish between deliberate redeem by owner and fraudulent redeem by anybody else with custom built long range NFC antenna? Any ideas? The firmcoin has two capacitive buttons that you have to press in sequence to redeem to coins. No long range antenna can do that. Best regards, Sergio. PS: the device has patents pending -- Accelerate Dev Cycles with Automated Cross-Browser Testing - For FREE Instantly run your Selenium tests across 300+ browser/OS combos. Get unparalleled scalability from the best Selenium testing platform available Simple to use. Nothing to install. Get started now for free. http://p.sf.net/sfu/SauceLabs___ Bitcoin-development mailing list Bitcoin-development@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/bitcoin-development
Re: [Bitcoin-development] Paper Currency
Hmm, this is firmcoin thing looks like what I mean. They don't have a solution yet, and prices they quote smartcards are unacceptable, but if they will manage to get down in selfcost - that may work. Ok, I'll follow them and see what it will come to. Best regards, Alex Kotenko 2014-05-19 13:55 GMT+01:00 Sergio Lerner sergioler...@certimix.com: Alex, I think that what you are talking about more or less something like the Firmcoin Check: http://firmcoin.com/?p=92 On 18/05/2014 08:47 a.m., Alex Kotenko wrote: One problem we couldn't figure out here though - how to protect the notes from unauthorized redeem. Like if someone else tries to reach your wallet with his own NFC - how can we distinguish between deliberate redeem by owner and fraudulent redeem by anybody else with custom built long range NFC antenna? Any ideas? The firmcoin has two capacitive buttons that you have to press in sequence to redeem to coins. No long range antenna can do that. Best regards, Sergio. PS: the device has patents pending -- Accelerate Dev Cycles with Automated Cross-Browser Testing - For FREE Instantly run your Selenium tests across 300+ browser/OS combos. Get unparalleled scalability from the best Selenium testing platform available Simple to use. Nothing to install. Get started now for free. http://p.sf.net/sfu/SauceLabs___ Bitcoin-development mailing list Bitcoin-development@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/bitcoin-development
Re: [Bitcoin-development] Paper Currency
-BEGIN PGP SIGNED MESSAGE- Hash: SHA1 On 05/19/2014 02:21 PM, Mike Hearn wrote: Submitted with humility and some fear of getting laughed out of here... Off topic aside, a bunch of us have lately started to think about the atmosphere on this list and how to improve it. Nobody should have to fear getting flamed or laughed at for proposing ideas, even if they turn out to be silly ones. Gavin talked about this in his Bitcoin 2014 keynote and asked for someone to solve the forum trolling problem. You and Gavin could do a lot better by working on a Bitcoin social contract - a promise of what features will *never* be added (or taken away) from Bitcoin, because despite what you say it's not acceptable to propose anything at all. Maybe start with things like how the Bitcoin protocol will never be changed to allow for confiscation of funds, regardless of who might demand such a feature. You are willing to promise all users of Bitcoin that you'll never propose to steal their coins, aren't you? -BEGIN PGP SIGNATURE- Version: GnuPG v1 Comment: Using GnuPG with Thunderbird - http://www.enigmail.net/ iQEcBAEBAgAGBQJTekt4AAoJEMP3uyY4RQ214QgIAM3DdtAUTG63FG/r9Yg4dWb+ TXWoXRd9AYDg/SAirF6qV+r6K0vohMv8UJhCpX0OnNSOfxKcgVt2CnG8i3iWBRu1 V+LRFmaHkJ+vJLaR2lEdFKMc2DVuZUIXGH6jEgVo/dzFJGZ/GcoUwTBrZztjCHDy WbpuuIfV2ya1bqkhMOn78pDgkDfXBD7qWQsz0MTzSkPitT0AnUEPxCl3KBWizkdH shGwE4YNhRSX+yTBaFHVMqFb9LzExEWgIgkgghddKfJzj9REcw6wiotD3DvYaDl7 LPegCttg0vdG4YTVlTH0iMwFYC3qrw/Ab43uqLjTy7aWyFjhsPtKceTE3KpGDrk= =dRhy -END PGP SIGNATURE- 0x38450DB5.asc Description: application/pgp-keys -- Accelerate Dev Cycles with Automated Cross-Browser Testing - For FREE Instantly run your Selenium tests across 300+ browser/OS combos. Get unparalleled scalability from the best Selenium testing platform available Simple to use. Nothing to install. Get started now for free. http://p.sf.net/sfu/SauceLabs___ Bitcoin-development mailing list Bitcoin-development@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/bitcoin-development
Re: [Bitcoin-development] Paper Currency
-BEGIN PGP SIGNED MESSAGE- Hash: SHA256 On 19 May 2014 20:20:40 CEST, Justus Ranvier justusranv...@gmail.com wrote: You and Gavin could do a lot better by working on a Bitcoin social contract - a promise of what features will *never* be added (or taken away) from Bitcoin, because despite what you say it's not acceptable to propose anything at all. Maybe start with things like how the Bitcoin protocol will never be changed to allow for confiscation of funds, regardless of who might demand such a feature. Might be worth looking into the recent RFC 7258: Pervasive Monitoring Is an Attack for some guidance on how to write such a social contract. Re: Gavin, note the language in the foundation bylaws: Section 2.2 The Corporation shall promote and protect both the decentralized, distributed and private nature of the Bitcoin distributed-digital currency and transaction system as well as individual choice, participation and financial privacy when using such systems. You might want to do a pull-req to add fungibility and rejection of blacklists to that list; note Adam Back's comments on how fungibility and privacy are inherently linked. -BEGIN PGP SIGNATURE- Version: APG v1.1.1 iQFQBAEBCAA6BQJTek/ZMxxQZXRlciBUb2RkIChsb3cgc2VjdXJpdHkga2V5KSA8 cGV0ZUBwZXRlcnRvZGQub3JnPgAKCRAZnIM7qOfwhYPIB/9/mhDOei8uMGHmzK41 YdL2ezs4LMPLyCRbo9Eu7MDJAMBaMH4VUbomR0tJVPRS191ifa2F/xGYnbDvk/PG rLX86uPPMBxZqnVMgZLeKJkUHm3Zlkm1Ti58bMR8VVQuPazBBpkYtsvk+0+8j9su ke7Xq+OqUGOC03bM4bxtKyBCy1FrCJuFgZEywKhOjr6boANLctDRBZerPqQ4AcjP tHSAAImcesMhjc/N9LJ4MeygszzblYpdsQeiw8jvvyZI7vCSHuKb+hur+kCszYjD ygfY9QmoNye2yc0GLZd+kXSMwY6gLIvaAFhv2ElMTMiJ7btHtJJfyEaA9Ub4zEEY JKeO =DSjZ -END PGP SIGNATURE- -- Accelerate Dev Cycles with Automated Cross-Browser Testing - For FREE Instantly run your Selenium tests across 300+ browser/OS combos. Get unparalleled scalability from the best Selenium testing platform available Simple to use. Nothing to install. Get started now for free. http://p.sf.net/sfu/SauceLabs ___ Bitcoin-development mailing list Bitcoin-development@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/bitcoin-development
Re: [Bitcoin-development] Paper Currency
I had a long discussion recently with somebody who wants and has resources to do exactly this - paper currency representing bitcoins. Yet we've been thinking mostly about a centralized solution, where one party is producing and maintaining paper currency, with bitcoins tied to each note verifiable via blockchain. The points we've ended up is that it needs to be: - reloadable - NFC based So anybody can verify any notes instantly by just touching it with his phone, and so merchants could redeem the notes at the moment of accepting it, convert it into fully online bitcoins and avoid costs of maintaining paper money turnover. Probably merchant would sell back redeemed empty notes to the issuer for a price of the note issue, and issuer will recharge it and put back into circulation. One problem we couldn't figure out here though - how to protect the notes from unauthorized redeem. Like if someone else tries to reach your wallet with his own NFC - how can we distinguish between deliberate redeem by owner and fraudulent redeem by anybody else with custom built long range NFC antenna? Any ideas? Best regards, Alex Kotenko 2014-05-17 17:40 GMT+01:00 Gregory Maxwell gmaxw...@gmail.com: On Sat, May 17, 2014 at 9:07 AM, Chris Pacia ctpa...@gmail.com wrote: I can't really just hand someone the note and walk away because they have to scan it to see if it is actually valid. Not just scan it, but they actually must successfully sweep it— otherwise they can be trivially double spent. This is especially bad since any prior bearer can perform such an attack. E.g. record the private key of everyone that passes through your hands and then doublespend race any redemption that happens 24 hours after you spend them. The wrong person would likely be blamed and even if you were blamed you could plausibly deny it (Must have been the guy that gave it to me!). Othercoin seems to have much better properties in the space of offline transactions: https://bitcointalk.org/index.php?topic=319146.0 Separately, Cassius also ran into some regulatory issues selling physical bitcoin artifacts. Especially printing things that seem to be redeemable for a named USD value sounds especially problematic. Some random comments— The base58 encoding is fairly human unfriendly. It's fine for something being copy and pasted, but I've found typing or reading it works poorly due to mixed case. I expect the A/B side to be difficult to educate users about. This side is private is more easily understood, you could just pick one of your sides and call it private. I find it kind of odd that this design seems to have no facility for checking its txouts without recovering the private key, though considering no one should rely on such a measurement without sweeping perhaps thats for the best. (As far as the numbering goes, I think you should be calling these draft-felix-paper-currency etc. As a matter of hygienic practice I will not assign a matching bip number for something that went public with a number outside of the assignment.) -- Accelerate Dev Cycles with Automated Cross-Browser Testing - For FREE Instantly run your Selenium tests across 300+ browser/OS combos. Get unparalleled scalability from the best Selenium testing platform available Simple to use. Nothing to install. Get started now for free. http://p.sf.net/sfu/SauceLabs ___ Bitcoin-development mailing list Bitcoin-development@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/bitcoin-development -- Accelerate Dev Cycles with Automated Cross-Browser Testing - For FREE Instantly run your Selenium tests across 300+ browser/OS combos. Get unparalleled scalability from the best Selenium testing platform available Simple to use. Nothing to install. Get started now for free. http://p.sf.net/sfu/SauceLabs___ Bitcoin-development mailing list Bitcoin-development@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/bitcoin-development
Re: [Bitcoin-development] Paper Currency
One problem we couldn't figure out here though - how to protect the notes from unauthorized redeem. Like if someone else tries to reach your wallet with his own NFC - how can we distinguish between deliberate redeem by owner and fraudulent redeem by anybody else with custom built long range NFC antenna? Any ideas? I think you'd need multiple factors to protect against that attack. Like encrypting with a key that is printed on the note as an QR code. -- Accelerate Dev Cycles with Automated Cross-Browser Testing - For FREE Instantly run your Selenium tests across 300+ browser/OS combos. Get unparalleled scalability from the best Selenium testing platform available Simple to use. Nothing to install. Get started now for free. http://p.sf.net/sfu/SauceLabs ___ Bitcoin-development mailing list Bitcoin-development@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/bitcoin-development
Re: [Bitcoin-development] Paper Currency
Yes, but it must not sacrifice usability. It's paper money, people are used to it and they have rather high standard of expectations in this area. Any usbility sacrifices in this area result into failure of the whole thing. Best regards, Alex Kotenko 2014-05-18 13:14 GMT+01:00 Andreas Schildbach andr...@schildbach.de: One problem we couldn't figure out here though - how to protect the notes from unauthorized redeem. Like if someone else tries to reach your wallet with his own NFC - how can we distinguish between deliberate redeem by owner and fraudulent redeem by anybody else with custom built long range NFC antenna? Any ideas? I think you'd need multiple factors to protect against that attack. Like encrypting with a key that is printed on the note as an QR code. -- Accelerate Dev Cycles with Automated Cross-Browser Testing - For FREE Instantly run your Selenium tests across 300+ browser/OS combos. Get unparalleled scalability from the best Selenium testing platform available Simple to use. Nothing to install. Get started now for free. http://p.sf.net/sfu/SauceLabs ___ Bitcoin-development mailing list Bitcoin-development@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/bitcoin-development -- Accelerate Dev Cycles with Automated Cross-Browser Testing - For FREE Instantly run your Selenium tests across 300+ browser/OS combos. Get unparalleled scalability from the best Selenium testing platform available Simple to use. Nothing to install. Get started now for free. http://p.sf.net/sfu/SauceLabs___ Bitcoin-development mailing list Bitcoin-development@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/bitcoin-development
Re: [Bitcoin-development] Paper Currency
Now you are talking about Trusted Platform Modules. Like smartcards, actually. Devices that won't leak their keys but let the holder spend the coins. It could even have it's own simple SPV wallet client to make it easier to handle. And they'd use the attestation features provided by the TPM to prove the software it's unmodified top the current holder. But then you still have to trust the manufacturer of the device, and you have to trust it has no exploitable side channels. - Sent from my phone Den 18 maj 2014 13:52 skrev Alex Kotenko alexy...@gmail.com: I had a long discussion recently with somebody who wants and has resources to do exactly this - paper currency representing bitcoins. Yet we've been thinking mostly about a centralized solution, where one party is producing and maintaining paper currency, with bitcoins tied to each note verifiable via blockchain. The points we've ended up is that it needs to be: - reloadable - NFC based So anybody can verify any notes instantly by just touching it with his phone, and so merchants could redeem the notes at the moment of accepting it, convert it into fully online bitcoins and avoid costs of maintaining paper money turnover. Probably merchant would sell back redeemed empty notes to the issuer for a price of the note issue, and issuer will recharge it and put back into circulation. One problem we couldn't figure out here though - how to protect the notes from unauthorized redeem. Like if someone else tries to reach your wallet with his own NFC - how can we distinguish between deliberate redeem by owner and fraudulent redeem by anybody else with custom built long range NFC antenna? Any ideas? Best regards, Alex Kotenko 2014-05-17 17:40 GMT+01:00 Gregory Maxwell gmaxw...@gmail.com: On Sat, May 17, 2014 at 9:07 AM, Chris Pacia ctpa...@gmail.com wrote: I can't really just hand someone the note and walk away because they have to scan it to see if it is actually valid. Not just scan it, but they actually must successfully sweep it— otherwise they can be trivially double spent. This is especially bad since any prior bearer can perform such an attack. E.g. record the private key of everyone that passes through your hands and then doublespend race any redemption that happens 24 hours after you spend them. The wrong person would likely be blamed and even if you were blamed you could plausibly deny it (Must have been the guy that gave it to me!). Othercoin seems to have much better properties in the space of offline transactions: https://bitcointalk.org/index.php?topic=319146.0 Separately, Cassius also ran into some regulatory issues selling physical bitcoin artifacts. Especially printing things that seem to be redeemable for a named USD value sounds especially problematic. Some random comments— The base58 encoding is fairly human unfriendly. It's fine for something being copy and pasted, but I've found typing or reading it works poorly due to mixed case. I expect the A/B side to be difficult to educate users about. This side is private is more easily understood, you could just pick one of your sides and call it private. I find it kind of odd that this design seems to have no facility for checking its txouts without recovering the private key, though considering no one should rely on such a measurement without sweeping perhaps thats for the best. (As far as the numbering goes, I think you should be calling these draft-felix-paper-currency etc. As a matter of hygienic practice I will not assign a matching bip number for something that went public with a number outside of the assignment.) -- Accelerate Dev Cycles with Automated Cross-Browser Testing - For FREE Instantly run your Selenium tests across 300+ browser/OS combos. Get unparalleled scalability from the best Selenium testing platform available Simple to use. Nothing to install. Get started now for free. http://p.sf.net/sfu/SauceLabs ___ Bitcoin-development mailing list Bitcoin-development@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/bitcoin-development -- Accelerate Dev Cycles with Automated Cross-Browser Testing - For FREE Instantly run your Selenium tests across 300+ browser/OS combos. Get unparalleled scalability from the best Selenium testing platform available Simple to use. Nothing to install. Get started now for free. http://p.sf.net/sfu/SauceLabs ___ Bitcoin-development mailing list Bitcoin-development@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/bitcoin-development -- Accelerate Dev Cycles with Automated Cross-Browser Testing - For FREE Instantly run
Re: [Bitcoin-development] Paper Currency
Jerry, some feedback on generating space-efficient QR codes. QR codes have 4 possible encodings, see Storage: http://en.wikipedia.org/wiki/QR_code The encoding you're proposing in BIP81 switches you to binary mode without actually using all the bits. So you'll end up with bloaty QR codes. One fix would be of course use all the available bits. However, binary QR codes cannot be used to auto-dispatch to apps on Android. If you want a wallet app to automatically open upon scan, you need to encode your data as an URI. That pretty much locks you into using alphanumeric mode QR codes. I've implemented that in Bitcoin Wallet for efficiently encoding transactions and BIP70 payment requests into QR codes. Since the allowed alphabet is 43 chars, I've named the encoding Base43 (it uses the same algorithm as Base58 or Base64). Tell me if you're interested in the details. On 05/17/2014 05:31 PM, Jerry Felix wrote: It seems to me that there's a huge need for a paper currency that is counterfeit-resistant, inexpensive to print, internationally recognized (border-less), fits in a wallet, and machine readable. I pitched this idea at the Cincinnati Bitcoin meetup last week, and I didn't get thrown out, so I took the time to document a proposed standard to accomplish this. I've put my ideas into BIP format, so that you can see what I have in mind, although I picked some BIP numbers myself that seem to be available. Call them proposed proposals, or provisional BIPs. I've numbered them provisionally BIP-80 to BIP-84. If you guys think that this idea has some merit, let's discuss. https://github.com/jerfelix/provisional_bips/blob/master/README.mediawiki Submitted with humility and some fear of getting laughed out of here... - Jerry -- Accelerate Dev Cycles with Automated Cross-Browser Testing - For FREE Instantly run your Selenium tests across 300+ browser/OS combos. Get unparalleled scalability from the best Selenium testing platform available Simple to use. Nothing to install. Get started now for free. http://p.sf.net/sfu/SauceLabs ___ Bitcoin-development mailing list Bitcoin-development@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/bitcoin-development -- Accelerate Dev Cycles with Automated Cross-Browser Testing - For FREE Instantly run your Selenium tests across 300+ browser/OS combos. Get unparalleled scalability from the best Selenium testing platform available Simple to use. Nothing to install. Get started now for free. http://p.sf.net/sfu/SauceLabs ___ Bitcoin-development mailing list Bitcoin-development@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/bitcoin-development
Re: [Bitcoin-development] Paper Currency
Erm, few things here. - I can't see really how to embed electronics capable to run an SPV client into printed paper. I know that passive NFC tags can be printed on paper, but not actual chips and/or power modules. So we are talking about a completely different things here. - even with paper notes printed proprietarily by some business the notes itself still can have routes for independent blockchain-based verification, and you won't need to trust anybody to test it. You will have to trust security of the notes itself, but this is same as when you trust the phone manufacturer when you're putting your bitcoin wallet on it. So really I see only issues of technical security in here, and this is the problem I'm seeking solutions for. Best regards, Alex Kotenko 2014-05-18 14:50 GMT+01:00 Natanael natanae...@gmail.com: Now you are talking about Trusted Platform Modules. Like smartcards, actually. Devices that won't leak their keys but let the holder spend the coins. It could even have it's own simple SPV wallet client to make it easier to handle. And they'd use the attestation features provided by the TPM to prove the software it's unmodified top the current holder. But then you still have to trust the manufacturer of the device, and you have to trust it has no exploitable side channels. - Sent from my phone Den 18 maj 2014 13:52 skrev Alex Kotenko alexy...@gmail.com: -- Accelerate Dev Cycles with Automated Cross-Browser Testing - For FREE Instantly run your Selenium tests across 300+ browser/OS combos. Get unparalleled scalability from the best Selenium testing platform available Simple to use. Nothing to install. Get started now for free. http://p.sf.net/sfu/SauceLabs___ Bitcoin-development mailing list Bitcoin-development@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/bitcoin-development
Re: [Bitcoin-development] Paper Currency
The problem with not involving any electronics is that somebody needs to generate a recoverable private key that we have to trust haven't recovered the private key. The only plausible solution is multisignature P2SH addresses where you trust several independent entities to not collude instead, where you combine their paper notes into one piece. And then you still don't know if all the private keys are recoverable to you (failed print?). - Sent from my phone Den 18 maj 2014 20:48 skrev Alex Kotenko alexy...@gmail.com: Erm, few things here. - I can't see really how to embed electronics capable to run an SPV client into printed paper. I know that passive NFC tags can be printed on paper, but not actual chips and/or power modules. So we are talking about a completely different things here. - even with paper notes printed proprietarily by some business the notes itself still can have routes for independent blockchain-based verification, and you won't need to trust anybody to test it. You will have to trust security of the notes itself, but this is same as when you trust the phone manufacturer when you're putting your bitcoin wallet on it. So really I see only issues of technical security in here, and this is the problem I'm seeking solutions for. Best regards, Alex Kotenko 2014-05-18 14:50 GMT+01:00 Natanael natanae...@gmail.com: Now you are talking about Trusted Platform Modules. Like smartcards, actually. Devices that won't leak their keys but let the holder spend the coins. It could even have it's own simple SPV wallet client to make it easier to handle. And they'd use the attestation features provided by the TPM to prove the software it's unmodified top the current holder. But then you still have to trust the manufacturer of the device, and you have to trust it has no exploitable side channels. - Sent from my phone Den 18 maj 2014 13:52 skrev Alex Kotenko alexy...@gmail.com: -- Accelerate Dev Cycles with Automated Cross-Browser Testing - For FREE Instantly run your Selenium tests across 300+ browser/OS combos. Get unparalleled scalability from the best Selenium testing platform available Simple to use. Nothing to install. Get started now for free. http://p.sf.net/sfu/SauceLabs___ Bitcoin-development mailing list Bitcoin-development@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/bitcoin-development
Re: [Bitcoin-development] Paper Currency
On Saturday, 17 May 2014, at 11:31 am, Jerry Felix wrote: I picked some BIP numbers myself that seem to be available. I'm quite certain you're explicitly *NOT* supposed to do this. -- Accelerate Dev Cycles with Automated Cross-Browser Testing - For FREE Instantly run your Selenium tests across 300+ browser/OS combos. Get unparalleled scalability from the best Selenium testing platform available Simple to use. Nothing to install. Get started now for free. http://p.sf.net/sfu/SauceLabs ___ Bitcoin-development mailing list Bitcoin-development@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/bitcoin-development
Re: [Bitcoin-development] Paper Currency
Since these notes have to be redeemed immediately the number of use cases seems limited. I can't really just hand someone the note and walk away because they have to scan it to see if it is actually valid. Otherwise someone could just pass fake notes if they felt the recipient wouldn't redeem them on the spot. This doesn't seem like an improvement over just sending the coins via phone. The use case with poor internet connection wouldn't work as well since, presumably, the recipient would also have poor reception and couldn't verify the note was actually loaded with bitcoins. Also, I REALLY don't like the name bit reserve. -Chris On 05/17/2014 11:31 AM, Jerry Felix wrote: It seems to me that there's a huge need for a paper currency that is counterfeit-resistant, inexpensive to print, internationally recognized (border-less), fits in a wallet, and machine readable. I pitched this idea at the Cincinnati Bitcoin meetup last week, and I didn't get thrown out, so I took the time to document a proposed standard to accomplish this. I've put my ideas into BIP format, so that you can see what I have in mind, although I picked some BIP numbers myself that seem to be available. Call them proposed proposals, or provisional BIPs. I've numbered them provisionally BIP-80 to BIP-84. If you guys think that this idea has some merit, let's discuss. https://github.com/jerfelix/provisional_bips/blob/master/README.mediawiki Submitted with humility and some fear of getting laughed out of here... - Jerry -- Accelerate Dev Cycles with Automated Cross-Browser Testing - For FREE Instantly run your Selenium tests across 300+ browser/OS combos. Get unparalleled scalability from the best Selenium testing platform available Simple to use. Nothing to install. Get started now for free. http://p.sf.net/sfu/SauceLabs ___ Bitcoin-development mailing list Bitcoin-development@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/bitcoin-development -- Accelerate Dev Cycles with Automated Cross-Browser Testing - For FREE Instantly run your Selenium tests across 300+ browser/OS combos. Get unparalleled scalability from the best Selenium testing platform available Simple to use. Nothing to install. Get started now for free. http://p.sf.net/sfu/SauceLabs___ Bitcoin-development mailing list Bitcoin-development@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/bitcoin-development
Re: [Bitcoin-development] Paper Currency
On Sat, May 17, 2014 at 9:07 AM, Chris Pacia ctpa...@gmail.com wrote: I can't really just hand someone the note and walk away because they have to scan it to see if it is actually valid. Not just scan it, but they actually must successfully sweep it— otherwise they can be trivially double spent. This is especially bad since any prior bearer can perform such an attack. E.g. record the private key of everyone that passes through your hands and then doublespend race any redemption that happens 24 hours after you spend them. The wrong person would likely be blamed and even if you were blamed you could plausibly deny it (Must have been the guy that gave it to me!). Othercoin seems to have much better properties in the space of offline transactions: https://bitcointalk.org/index.php?topic=319146.0 Separately, Cassius also ran into some regulatory issues selling physical bitcoin artifacts. Especially printing things that seem to be redeemable for a named USD value sounds especially problematic. Some random comments— The base58 encoding is fairly human unfriendly. It's fine for something being copy and pasted, but I've found typing or reading it works poorly due to mixed case. I expect the A/B side to be difficult to educate users about. This side is private is more easily understood, you could just pick one of your sides and call it private. I find it kind of odd that this design seems to have no facility for checking its txouts without recovering the private key, though considering no one should rely on such a measurement without sweeping perhaps thats for the best. (As far as the numbering goes, I think you should be calling these draft-felix-paper-currency etc. As a matter of hygienic practice I will not assign a matching bip number for something that went public with a number outside of the assignment.) -- Accelerate Dev Cycles with Automated Cross-Browser Testing - For FREE Instantly run your Selenium tests across 300+ browser/OS combos. Get unparalleled scalability from the best Selenium testing platform available Simple to use. Nothing to install. Get started now for free. http://p.sf.net/sfu/SauceLabs ___ Bitcoin-development mailing list Bitcoin-development@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/bitcoin-development
