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Topic: How would you like to design a bitcoin banknote? - page 16. (Read 94820 times)

vip
Activity: 1386
Merit: 1140
The Casascius 1oz 10BTC Silver Round (w/ Gold B)
I still plan to pay out on it, and I would say my objective has been met.
member
Activity: 98
Merit: 10
(:firstbits => "1mantis")
Has this project been abandoned?  Cry
member
Activity: 98
Merit: 10
(:firstbits => "1mantis")
member
Activity: 98
Merit: 10
(:firstbits => "1mantis")
How is it going with finishing up? I can't wait to try it out!
member
Activity: 98
Merit: 10
(:firstbits => "1mantis")
vip
Activity: 1386
Merit: 1140
The Casascius 1oz 10BTC Silver Round (w/ Gold B)
How about a design that is more descrete. Perhaps like a lottery ticket with a barcode instead of a qr code?

A QR code is a barcode.  Maybe you mean a 1-dimensional barcode rather than a 2-dimensional barcode.  The whole point of 2-dimensional barcodes is to increase the amount of data you can fit.  1-dimensional barcodes aren't suitable for bitcoin keys due to their size.  No commonly-used 1d barcode symbology supports mixed case text.

2d barcodes also add advanced error correction that can tolerate a total loss of a certain percentage of the code, something that would be desirable in a cash application, and something 1d barcodes don't offer.
member
Activity: 98
Merit: 10
(:firstbits => "1mantis")
I agree. There is no security advantage to having the public key if the private key is also visible. To verify the balance, or even load the address securely, you need to know that the private key matches the public key anyway, so the public key isn't sufficient. You might as well include only the private key, from which the public key can be generated; there is no need for a special encoding. That also simplifies the design (one QR code per certificate).

I'd make it an option... like a checkbox... I could see others agreeing the bitcoin QR isn't needed while at the same time others saying it is needed.

I would enjoy these particular advantages having the public key.

* the ability to get the bitcoin address into a computer with a USB keyboard wedge barcode scanner without hand-pecking each character, so I can fund the note, or use block explorer, or e-mail the bitcoin address to somebody in anticipation of a payment.  (Remember, just because the bitcoin address could be calculated, doesn't mean that anything will calculate it!  And the keyboard-emulating barcode scanner is an example of something that sure isn't going to.)
* the ability to use the note to accept change from a transaction, or incoming payments, without giving away the opportunity to claw it back
* the ability to use a shared resource to confirm for my own benefit that the balance on the note is what I think it is (think similar to a price-check kiosk at Target)
* the ability to fund notes that will be used for safekeeping/storage and have 100% assurance that the private key wasn't captured by the funding computer (this matters mainly for large amounts, not so much for smaller ones)


How about a design that is more descrete. Perhaps like a lottery ticket with a barcode instead of a qr code?
vip
Activity: 1386
Merit: 1140
The Casascius 1oz 10BTC Silver Round (w/ Gold B)
I agree. There is no security advantage to having the public key if the private key is also visible. To verify the balance, or even load the address securely, you need to know that the private key matches the public key anyway, so the public key isn't sufficient. You might as well include only the private key, from which the public key can be generated; there is no need for a special encoding. That also simplifies the design (one QR code per certificate).

I'd make it an option... like a checkbox... I could see others agreeing the bitcoin QR isn't needed while at the same time others saying it is needed.

I would enjoy these particular advantages having the public key.

* the ability to get the bitcoin address into a computer with a USB keyboard wedge barcode scanner without hand-pecking each character, so I can fund the note, or use block explorer, or e-mail the bitcoin address to somebody in anticipation of a payment.  (Remember, just because the bitcoin address could be calculated, doesn't mean that anything will calculate it!  And the keyboard-emulating barcode scanner is an example of something that sure isn't going to.)
* the ability to use the note to accept change from a transaction, or incoming payments, without giving away the opportunity to claw it back
* the ability to use a shared resource to confirm for my own benefit that the balance on the note is what I think it is (think similar to a price-check kiosk at Target)
* the ability to fund notes that will be used for safekeeping/storage and have 100% assurance that the private key wasn't captured by the funding computer (this matters mainly for large amounts, not so much for smaller ones)
donator
Activity: 1736
Merit: 1014
Let's talk governance, lipstick, and pigs.
You might as well include only the private key
I think that's the way to go. And the design of the note should allow folding to conceal the key. Folding over a corner to conceal a substantial portion of the QR-code would be sufficient.
All the public key does is to allow a payment to the bitcoin address for someone that doesn't own that address. If the bill is for a fixed amount then you do not need a public key and only need the value in BTC printed.
full member
Activity: 152
Merit: 100
Why not have just one QR-code, encoded in such a way that it cointains both the private key and the public key? This forces people to read both keys, and makes it easy to check that the private key can spend funds sent to a receiving address generated from the public key.

This would remove the temptation to scan only the "verify" address and assume that the balance associated with that address can be spent.

I agree. There is no security advantage to having the public key if the private key is also visible. To verify the balance, or even load the address securely, you need to know that the private key matches the public key anyway, so the public key isn't sufficient. You might as well include only the private key, from which the public key can be generated; there is no need for a special encoding. That also simplifies the design (one QR code per certificate).
vip
Activity: 1386
Merit: 1140
The Casascius 1oz 10BTC Silver Round (w/ Gold B)
Hang on a moment. You can scan the public address to see whether it holds coins, but you have no way to verify that the supplied private key will let you spend those coins. The only way you can possibly verify that the note holds value is to spend the note.

Therefore the public QR-code should not be labelled "Verify". Even "Load" is dubious, as you might be loading some scammer's address with your coins.

That's why you should print these yourself with a program you trust on a machine you know isn't hacked.  You aren't going to be loading bills that others printed for you.  When you actually spend the bill, all that matters is that they are able to sweep funds when scanning just the private key.

Any shenanigans and you will inconvenience only yourself.  Try going to Home Depot, put a tool in your cart, grab a new gift card off the shelf, and attempt to use the gift card to pay for the tools.  It won't work, anyone can guess it will be because the gift card has a balance of 0.00, and you'll only be wasting your own time.
member
Activity: 98
Merit: 10
(:firstbits => "1mantis")
Thanks a lot.

Will also post a green revision which uses much less ink.

Wait a couple days and I'll post the SVG here and on the designer blog @ http://ocantinhodadama.clinicadosom.com/2012/07/20/bitcoin-note-design-psd-file/


Looking forward to perhaps established denominations like the Euro?
legendary
Activity: 1358
Merit: 1002
Thanks a lot.

Will also post a green revision which uses much less ink.

Wait a couple days and I'll post the SVG here and on the designer blog @ http://ocantinhodadama.clinicadosom.com/2012/07/20/bitcoin-note-design-psd-file/
legendary
Activity: 924
Merit: 1004
Firstbits: 1pirata
sr. member
Activity: 352
Merit: 250
Congratzz Cheesy
member
Activity: 98
Merit: 10
(:firstbits => "1mantis")
Once everyone has one of these, literally seeing such a banknote means owning it.

True!

See Mike! THIS is why I am all paranoid Tongue

I think covering the QR code with a Post-It note or a folded flap will be a lot more practical than a scheme where the bill has to be precisely cut or folded to be spent.  Remember, the whole prototypical point of this is speed and convenience for laypeople at a retail checkout scenario.  Anyone can rip off a Post-It note in less than a second, and anyone who can buy a printer can also buy a pad of Post-It notes anywhere in the world.

Since this whole effort is going to be public domain / open source, it comes with a license for anyone to do near whatever the f- they want with it, so no one will stop you from making and publishing a bill that must be folded like MAD Magazine.  But it's outside of the scope of my stated intent for this particular effort.

I think I have just about got the reward payout scheme just about finalized.  And the gracious donation of 10BTC, I think I am going to say should go to the person who successfully marries the BitAddress.org codebase with the SVG version of what is pretty much certainly the first-place winner: the banknote presented to us by Psy.

CONGRATULATIONS PSY!

I can't WAIT to try it!
vip
Activity: 1386
Merit: 1140
The Casascius 1oz 10BTC Silver Round (w/ Gold B)
Once everyone has one of these, literally seeing such a banknote means owning it.

True!

See Mike! THIS is why I am all paranoid Tongue

I think covering the QR code with a Post-It note or a folded flap will be a lot more practical than a scheme where the bill has to be precisely cut or folded to be spent.  Remember, the whole prototypical point of this is speed and convenience for laypeople at a retail checkout scenario.  Anyone can rip off a Post-It note in less than a second, and anyone who can buy a printer can also buy a pad of Post-It notes anywhere in the world.

Since this whole effort is going to be public domain / open source, it comes with a license for anyone to do near whatever the f- they want with it, so no one will stop you from making and publishing a bill that must be folded like MAD Magazine.  But it's outside of the scope of my stated intent for this particular effort.

I think I have just about got the reward payout scheme just about finalized.  And the gracious donation of 10BTC, I think I am going to say should go to the person who successfully marries the BitAddress.org codebase with the SVG version of what is pretty much certainly the first-place winner: the banknote presented to us by Psy.
member
Activity: 98
Merit: 10
(:firstbits => "1mantis")
Once everyone has one of these, literally seeing such a banknote means owning it.

True!

See Mike! THIS is why I am all paranoid Tongue
aq
full member
Activity: 238
Merit: 100
Once everyone has one of these, literally seeing such a banknote means owning it.
legendary
Activity: 924
Merit: 1004
Firstbits: 1pirata
How is this going guys? We plan ending the contest on Rugatu almost at the same time with yours Smiley

http://www.rugatu.com/questions/1833/how-would-you-like-to-design-a-bitcoin-banknote
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