How would you like to design a bitcoin banknote? - page 9.

salfter

hero member

Activity: 651

Merit: 501

My PGP Key: 92C7689C

Quote from: Rudd-O on December 03, 2012, 07:11:30 PM

How do the Load and Verify QR codes work? What prevents someone from just filching value from the bill?

The intent is that before they enter circulation, you would apply some sort of tamper-evident seal over the private key. This seal would only be removed if you intended to take the note out of circulation.

The public key is left uncovered so you can verify that the note contains the indicated value.

ercolinux

legendary

Activity: 938

Merit: 1000

Quote from: salfter on December 03, 2012, 06:22:43 PM

A minor update to my generator:

https://github.com/salfter/btcnotes/

The back pattern has been rotated 90 degrees so the URLs show up better on the finished notes. Next update will more than likely add more denominations (at least BTC0.1 and BTC0.2, and maybe some bigger notes) in more colors.

Here's an example of the output of this version:

https://dl.dropbox.com/u/57535575/job3860.pdf

Nice job. If you reduce a little the images you can print 6 on a page, that's even better

odolvlobo

legendary

Activity: 4466

Merit: 3391

Quote from: Rudd-O on December 03, 2012, 07:11:30 PM

How do the Load and Verify QR codes work? What prevents someone from just filching value from the bill?

"Load and Verify" shows the address that holds the BTC. You use it to verify that the address actually has the expected amount of BTC.

The private key is displayed on the note, so nothing except careful handling prevents someone from stealing the coins from the note. It is designed for one-time use, and is not suitable to be used as currency.

Rudd-O

newbie

Activity: 56

Merit: 0

How do the Load and Verify QR codes work? What prevents someone from just filching value from the bill?

salfter

hero member

Activity: 651

Merit: 501

My PGP Key: 92C7689C

A minor update to my generator:

https://github.com/salfter/btcnotes/

The back pattern has been rotated 90 degrees so the URLs show up better on the finished notes. Next update will more than likely add more denominations (at least BTC0.1 and BTC0.2, and maybe some bigger notes) in more colors.

Here's an example of the output of this version:

https://dl.dropbox.com/u/57535575/job3860.pdf

casascius

vip

Activity: 1386

Merit: 1140

The Casascius 1oz 10BTC Silver Round (w/ Gold B)

Quote from: fivemileshigh on December 02, 2012, 05:42:10 AM

Is there a mac version of the note-printer utility? thanks!

There's a web version available at bitaddress.org.

My understanding is it can be compiled for Mono (probably only if you're into compiling stuff yourself, this won't be point-and-click). And it certainly runs under Windows using Parallels, Bootcamp, or any solution allowing Windows itself to run on a Mac.

fivemileshigh

full member

Activity: 136

Merit: 100

Is there a mac version of the note-printer utility? thanks!

casascius

vip

Activity: 1386

Merit: 1140

The Casascius 1oz 10BTC Silver Round (w/ Gold B)

My alpha version (source on github, binary+source at https://casascius.com/btcaddress-alpha.zip ) allows the creation of two-factor passphrase-protected notes.

If one computer is used to hash the passphrase, and you transfer the hashed version of it to another computer to produce the notes (via the "intermediate generator"), it would require a compromise of both machines for anyone to be able to decrypt the notes.

Mushroomized

legendary

Activity: 1470

Merit: 1002

Hello!

So do you guys have any ideas how to use these for offline storage? I mean aside from genning the keys offline, printing them and storing them, do you guys do anything else to be super safe

Elxiliath

member

Activity: 66

Merit: 10

Wow, this application is awesome!!! I tried to do something like this myself, but it wasn't so easy. Thanks so much for this Cas!

dserrano5

legendary

Activity: 1974

Merit: 1029

Quote from: kangasbros on November 20, 2012, 02:17:10 PM

Wrote a blog post about paper wallets: http://localbitcoins.blogspot.fi/2012/11/start-your-own-money-press.html

What do you mean "Printer manufacturers are controlled by reptilians"? Is it actually insecure to print something sensitive, then connect the printer to an internet-connected machine? Even when power cycling it?

kangasbros

hero member

Activity: 812

Merit: 1006

Wrote a blog post about paper wallets: http://localbitcoins.blogspot.fi/2012/11/start-your-own-money-press.html

salfter

hero member

Activity: 651

Merit: 501

My PGP Key: 92C7689C

I've updated my generator:

https://github.com/salfter/btcnotes/

It now produces 3/4" squares with human-readable privkeys that can be placed over the privkey QR codes before applying your tamper-evident labels. Black boxes are also generated on the back opposite the privkey QR codes; if nothing else, they'll help you line up the label on the back.

Here's an example of the output of this version:

https://dl.dropbox.com/u/57535575/job5456.pdf

Mjbmonetarymetals

legendary

Activity: 1096

Merit: 1067

Not sure if this has been mentioned on the thread -

http://www.youtube.com/watch?v=cLu5baef90g&feature=youtube_gdata_player

Mushroomized

legendary

Activity: 1470

Merit: 1002

Hello!

Quote from: kangasbros on November 15, 2012, 07:57:57 AM

I wanted something extremely simple & something that is cheap to print. So that they can use these in Africa

kangasbros

hero member

Activity: 812

Merit: 1006

My take: https://github.com/kangasbros/skimpybtcnotes

I wanted something extremely simple & something that is cheap to print. So that they can use these in Africa

Banknotes:

Storage sheets:

salfter

hero member

Activity: 651

Merit: 501

My PGP Key: 92C7689C

Quote from: teflone on November 13, 2012, 06:35:51 PM

point me to a link that generates those with a unique private key... (wallet)

If you're referring to my project, you need to clone it from the GitHub repo, make sure you have the software (including vanitygen) listed under Prerequisites in the README, and run the script. Each run generates new privkeys for each note. It's intended for offline use; it's not offered as a web service.

If you're referring to something else, never mind.

Mushroomized

legendary

Activity: 1470

Merit: 1002

Hello!

Quote from: salfter on November 13, 2012, 08:26:42 PM

Quote from: Mushroomized on November 13, 2012, 08:10:36 PM

Quote from: salfter on November 13, 2012, 06:23:18 PM

I've put together an offline note generator:

https://github.com/salfter/btcnotes/

I think the notes should go from 1-256, each .01 raising the hue level a bit, that way it will give a cool effect, Wink

I was aiming for standard denominations that mirror existing paper currency. (At present value, I should probably do 0.1 and 0.2 BTC notes as well.)

But 1-256 is computery

salfter

hero member

Activity: 651

Merit: 501

My PGP Key: 92C7689C

Quote from: Mushroomized on November 13, 2012, 08:10:36 PM

Quote from: salfter on November 13, 2012, 06:23:18 PM

I've put together an offline note generator:

https://github.com/salfter/btcnotes/

I think the notes should go from 1-256, each .01 raising the hue level a bit, that way it will give a cool effect, Wink

I was aiming for standard denominations that mirror existing paper currency. (At present value, I should probably do 0.1 and 0.2 BTC notes as well.)

Mushroomized

legendary

Activity: 1470

Merit: 1002

Hello!

Quote from: salfter on November 13, 2012, 06:23:18 PM

I've put together an offline note generator:

https://github.com/salfter/btcnotes/

Notes are rendered four to a page. Five denominations (0.5,1, 2, 5, and 10 BTC) are currently supported, each of which prints in its own color. Addresses and private keys are generated on-the-fly, rendered as both text and QR codes. Page layout is done in PostScript with artwork that started out as SVG, so you get the highest print quality possible. For convenience, final output is to PDF. I considered using HTML and CSS to position SVG images directly, but print quality proved a bit hit-or-miss...Firefox was usually OK, but Chrome frequently rendered SVG elements at 72 dpi or so before printing. Even with Firefox, I sometimes had some unexplained print failures.

For sample output, try this:

https://dl.dropbox.com/u/57535575/job2948.pdf

I think the notes should go from 1-256, each .01 raising the hue level a bit, that way it will give a cool effect, Wink

Topic: How would you like to design a bitcoin banknote? - page 9. (Read 94806 times)