How would you like to design a bitcoin banknote?

[casascius]

Maybe what needs to be done is a version of BitAddress.org made, that loads a single static .js file in the same directory?  This would allow customizations to be done, and for them to be reviewed separately, while the mainline bitcoin address generator can stay unmodified and its integrity verified through a hash check.

That .js file might modify the styles a little bit to add an image and reposition the elements so they work.  That .js file would have slightly more freedom (e.g. it could reference a .png or .svg file in the same directory) but it would be very short and trivial to audit.

Nothing says there can't be more than one good style of banknote, and nothing says there can't be a repository of them.

"Think Different" is a registered trademark of Apple and probably isn't a good idea to use.

[casascius]

Just to follow up on my offer of compensation/reward:

I have budgeted USD $200 as rewards for the efforts going into this project.  There may very well be more than one winner.  However, to be in the running for any substantial portion of it, I need it to match a reasonable "definition of done".  "Definition of done" includes sending me an original file in native layered format (such as Photoshop) with the vector items intact so that they can be extracted to SVG elements.

I would like to note that Tony (Bit-Pay) has sent me his Photoshop file of what he has so far.

The previous submission that included the blue and grey fractal background... Where can I find this image in high resolution?  What is the copyright status on this image?

What I would really like to do is separate these submissions into layers so someone wanting to print bills can choose from several backgrounds, several portraits, and several designs, and the javascript would include the appropriate layers all by itself.

[TraderTimm]

I've been thinking about the private key part...

What if you could make a square 'matrix' that was surrounded by letters/numbers which would yield the proper QR-Code when you filled in the squares where they intersect? It would be like a cipher code that would prevent immediate 'cashing in' if someone found/stole it.

Layout Image Link:
https://docs.google.com/open?id=0BzdbolIn7zf1bEJ4Z3hqdC0wekU

The idea is that the QR Code would be 'degraded' by pixels being removed from the complete passphrase-revealing QR Code. I haven't run this in reverse to see what the degraded QR Code would generate - so that may be a problem with the scheme if it is very obvious what is missing.

Just throwing it out there...

UPDATE: Just tried to erase the one point where the example points to, and my QR reader was still able to get to the website - I suppose you'd have to tailor it to overcome some of the data redundancy inherent in QR Codes to make the scheme work. May still be valuable to someone, anyway.

[casascius]

The idea for a password-protected private key I had, was merely to do a normal private key code but substitute a different version byte so it starts with a different character than a '5', merely to indicate it's password protected.

The private key would be decrypted merely by XORing it with sha256(password).

The password would be deemed correct if money were found on the resulting address.  Alternatively, extra bytes could be added to the private key format to give between 8 and 16 bits of check bits on the password so that most typos could be automatically detected and rejected.

Security could be enhanced by substituting a computationally expensive key derivation algorithm in place of SHA256.

[Timbo925]

So I changed things around a bit. Separateness the QR codes so it is better for scanning.
The middle square would be great to make it fully cognizable with all the different photo's / backgrounds...



Maybe an idea for more protection is print half of the QR code on the front. Half on the back. Then if you fold the bill you can scan the code for redeeming.
The loading/looking part can still be on the front because you only can load funds and see how much the bill is worth.
This way you can easily check value and only if you want the balance off you need to do some work.

[btcprophet]

Instead of imitating the look of USD notes and putting pictures of random scientists and silly slogans of the 'in ${whatever} we trust' variety, I would really like to see a design that reflects some of Bitcoin's fundamental building blocks.

For example:

• shapes derived from elliptical curves that the ECDSA algorithm is based on
• watermark based on the bit patterns of the individual iterations of the SHA1 function (160 bits go through 80 steps which could be visualized as 160x80 bitmap)
• prime numbers!
• some reference to Bitcoin script - it's kind of key to the system yet many people are not even aware it exists
• express the peer to peer nature of the network
• symbolic representation of the block chain

I'm not knocking the existing designs but I do feel we could go for a little bit more depth and really revel in the mathematical roots of Bitcoin .

[bg002h]

Instead of imitating the look of USD notes and putting pictures of random scientists and silly slogans of the 'in ${whatever} we trust' variety, I would really like to see a design that reflects some of Bitcoin's fundamental building blocks.

For example:

• shapes derived from elliptical curves that the ECDSA algorithm is based on
• watermark based on the bit patterns of the individual iterations of the SHA1 function (160 bits go through 80 steps which could be visualized as 160x80 bitmap)
• prime numbers!
• some reference to Bitcoin script - it's kind of key to the system yet many people are not even aware it exists
• express the peer to peer nature of the network
• symbolic representation of the block chain

I'm not knocking the existing designs but I do feel we could go for a little bit more depth and really revel in the mathematical roots of Bitcoin .

Very insightful. Very tough to do well. Aim for the skies boys!

[Mushroomized]

Instead of imitating the look of USD notes and putting pictures of random scientists and silly slogans of the 'in ${whatever} we trust' variety, I would really like to see a design that reflects some of Bitcoin's fundamental building blocks.

For example:

• shapes derived from elliptical curves that the ECDSA algorithm is based on
• watermark based on the bit patterns of the individual iterations of the SHA1 function (160 bits go through 80 steps which could be visualized as 160x80 bitmap)
• prime numbers!
• some reference to Bitcoin script - it's kind of key to the system yet many people are not even aware it exists
• express the peer to peer nature of the network
• symbolic representation of the block chain

I'm not knocking the existing designs but I do feel we could go for a little bit more depth and really revel in the mathematical roots of Bitcoin .

Yep, I really think having the design change based on the current hashrate and blockcount at time of printing would be awesome

[2112]

but I do feel we could go for a little bit more depth and really revel in the mathematical roots of Bitcoin .

Just add to the requirements that in addition to decimal the numbers should be printed in tonal. Then Luke-Jr will do all your work for free and will contribute to the bounty.

[ErebusBat]

but I do feel we could go for a little bit more depth and really revel in the mathematical roots of Bitcoin .

Just add to the requirements that in addition to decimal the numbers should be printed in tonal. Then Luke-Jr will do all your work for free and will contribute to the bounty.

I need the story that goes with this.

[bg002h]

Too funny. I ne'er did follow that tonal thing...tl;dr kinda thing. Anyhow, Luke is a good guy. I wonder what he'd think about the designs. I know he's held at least one BitBill before.

[teflone]

after printing one out..

I think a bit bill should be the size of a folded bill..

And have it so that folded one specific way in half.. should hide the private key..  

Like so..  think of this as each side of the bill


 ----------------
| X                X |
|                      |     - Front
 ----------------

 ----------------
| X                O |
|                      |      - Back
 ----------------


X's being the public addy, O being the private key..

Printing it like this, with a fold in the right direction can serve to hide the key until needed..  or even seal the bill shut with any tamper evident seal if made small enough you couldnt just look inside the folded bill..  

[Stephen Gornick]

refresh this page one more time, they now say "Bitcoin Note" and "Bitcoin Bearer Bond"

A financial note is defined as a debt instrument, with maturity from one year to ten.    A banknote is a promissory note though they are no longer private instruments redeemable for precious metal but instead are national banknotes and thus fiat currency.

Is it safe to say the term note would be misused here?

Or does it even matter though?  It doesn't say banknote, it just says note.

And thus a bitcoin note can have the definition that it contains a private key that can be used for spending?

(full disclosure: I registered bitcoinnote.com, bitcoinnotes.com, btcnote.com, and btcnotes.com ... in anticipation that there would be the need for a paper bitcoin that would allow an inexpensive method for a trusted party to transfer bitcoins offline.)

[unclemantis]

refresh this page one more time, they now say "Bitcoin Note" and "Bitcoin Bearer Bond"

A financial note is defined as a debt instrument, with maturity from one year to ten.    A banknote is a promissory note though they are no longer private instruments redeemable for precious metal but instead are national banknotes and thus fiat currency.

Is it safe to say the term note would be misused here?

Or does it even matter though?  It doesn't say banknote, it just says note.

And thus a bitcoin note can have the definition that it contains a private key that can be used for spending?

(full disclosure: I registered bitcoinnote.com, bitcoinnotes.com, btcnote.com, and btcnotes.com ... in anticipation that there would be the need for a paper bitcoin that would allow an inexpensive method for a trusted party to transfer bitcoins offline.)

Voucher or Token or something that needs no other backing. Something like what you would call Gold, Silver, etc...

[apetersson]

i do not have a design suggestion but a practical one.

i think there should be self-printable bitcoins. those should secure the private key with a pin/password/pattern.
so if they get lost or stolen they are not as dangerous as "blanks". once a user wants to spend them he writes the pin on the bitcoin note, the reciever then uses this to redeem it.

of course, this only makes sense if the clients support it. but if you set the precedence im sure smart clients will follow.

[BitPay Business Solutions]

refresh this page one more time, they now say "Bitcoin Note" and "Bitcoin Bearer Bond"

A financial note is defined as a debt instrument, with maturity from one year to ten.    A banknote is a promissory note though they are no longer private instruments redeemable for precious metal but instead are national banknotes and thus fiat currency.

Is it safe to say the term note would be misused here?

Or does it even matter though?  It doesn't say banknote, it just says note.

And thus a bitcoin note can have the definition that it contains a private key that can be used for spending?

(full disclosure: I registered bitcoinnote.com, bitcoinnotes.com, btcnote.com, and btcnotes.com ... in anticipation that there would be the need for a paper bitcoin that would allow an inexpensive method for a trusted party to transfer bitcoins offline.)

Voucher or Token or something that needs no other backing. Something like what you would call Gold, Silver, etc...

Good points.  Notes are paper representation of a debt instrument.  What would you a call a paper representation of an asset?

[unclemantis]

refresh this page one more time, they now say "Bitcoin Note" and "Bitcoin Bearer Bond"

A financial note is defined as a debt instrument, with maturity from one year to ten.    A banknote is a promissory note though they are no longer private instruments redeemable for precious metal but instead are national banknotes and thus fiat currency.

Is it safe to say the term note would be misused here?

Or does it even matter though?  It doesn't say banknote, it just says note.

And thus a bitcoin note can have the definition that it contains a private key that can be used for spending?

(full disclosure: I registered bitcoinnote.com, bitcoinnotes.com, btcnote.com, and btcnotes.com ... in anticipation that there would be the need for a paper bitcoin that would allow an inexpensive method for a trusted party to transfer bitcoins offline.)

Voucher or Token or something that needs no other backing. Something like what you would call Gold, Silver, etc...

Good points.  Notes are paper representation of a debt instrument.  What would you a call a paper representation of an asset?

Is a PDF version of that Bitcoin Barer Bond available yet?

[bg002h]

refresh this page one more time, they now say "Bitcoin Note" and "Bitcoin Bearer Bond"

A financial note is defined as a debt instrument, with maturity from one year to ten.    A banknote is a promissory note though they are no longer private instruments redeemable for precious metal but instead are national banknotes and thus fiat currency.

Is it safe to say the term note would be misused here?

Or does it even matter though?  It doesn't say banknote, it just says note.

And thus a bitcoin note can have the definition that it contains a private key that can be used for spending?

(full disclosure: I registered bitcoinnote.com, bitcoinnotes.com, btcnote.com, and btcnotes.com ... in anticipation that there would be the need for a paper bitcoin that would allow an inexpensive method for a trusted party to transfer bitcoins offline.)

Voucher or Token or something that needs no other backing. Something like what you would call Gold, Silver, etc...

Good points.  Notes are paper representation of a debt instrument.  What would you a call a paper representation of an asset?

A deed or title I suppose...

[unclemantis]

refresh this page one more time, they now say "Bitcoin Note" and "Bitcoin Bearer Bond"

A financial note is defined as a debt instrument, with maturity from one year to ten.    A banknote is a promissory note though they are no longer private instruments redeemable for precious metal but instead are national banknotes and thus fiat currency.

Is it safe to say the term note would be misused here?

Or does it even matter though?  It doesn't say banknote, it just says note.

And thus a bitcoin note can have the definition that it contains a private key that can be used for spending?

(full disclosure: I registered bitcoinnote.com, bitcoinnotes.com, btcnote.com, and btcnotes.com ... in anticipation that there would be the need for a paper bitcoin that would allow an inexpensive method for a trusted party to transfer bitcoins offline.)

Voucher or Token or something that needs no other backing. Something like what you would call Gold, Silver, etc...

Good points.  Notes are paper representation of a debt instrument.  What would you a call a paper representation of an asset?

A deed or title I suppose...

Coupon?

[Bitcoin Oz]

What about paper stock certificates representing glbse shares ?