Print Page - Bitcoin Credit Card Design

Just something I did when I was board.

A sort of credit card design I made. Includes a SHA512 hash and a MD5 hash which I know.

Not done, but I'll work on it. If you feel like donating, please see my signature. Thanks!

http://i.creativecommons.org/l/by-nc-nd/3.0/88x31.png (http://creativecommons.org/licenses/by-nc-nd/3.0/)
Bitcoin Magnetic Card Designs by DarK_St3alth is licensed under a Creative Commons Attribution-NonCommercial-NoDerivs 3.0 Unported License.

Fronts:
http://img341.imageshack.us/img341/3673/frontj.th.png (http://img341.imageshack.us/img341/3673/frontj.png) http://img687.imageshack.us/img687/8274/front2d.th.png (http://img687.imageshack.us/img687/8274/front2d.png) http://img3.imageshack.us/img3/7326/front3.th.png (http://img3.imageshack.us/img3/7326/front3.png) http://img542.imageshack.us/img542/7326/front3.th.png (http://img542.imageshack.us/img542/7326/front3.png) http://img194.imageshack.us/img194/9596/front5.th.png (http://img194.imageshack.us/img194/9596/front5.png)

Backs (if you can print them):
http://img217.imageshack.us/img217/2120/backap.th.png (http://img217.imageshack.us/img217/2120/backap.png)

All images uploaded with ImageShack.us (http://imageshack.us)

Quote from: dark_st3alth on December 09, 2011, 05:03:16 AM

Frickin' nice! Very nice! Personally, I'm having trouble getting my head wrapped around the term 'Credit Card'. Perhaps a different word or term for what you have here is in order. Hopefully the community can help me (us) out with this issue I'm having.

Thoughts?

Frickin' nice! Very nice! Personally, I'm having trouble getting my head wrapped around the term 'Credit Card' . Perhaps a different word or term for what you have here is in order. Hopefully the community can help me (us) out with this issue I'm having.

I think the more appropriate term would be debit card.. Just instead of the funds coming out of your bank account, they'd come out of your wallet.

The only issue is.. since there is nothing on the card to allow you to "push" the funds by initiating a payment, a protocol would have to be developed for a "pull" transaction ... This does, of course, involve a level of trust in where you "swipe" your card since you would really have no control over the amount of the "pull" and no recourse if more-than-expected funds were taken from your wallet.

Siggy

We have become so accustomed to credit cards, it's hard to imagine life without them. A major problem with magnetic strips is that they are easily erased. Instead of a magnetic strip, why not just use cards loaded with small QR private key paper coins embedded. They can be removed and replaced after they are used. Change can be made to the public key. Backups can be kept stored with online wallet services in case the card is lost, and the Bitcoin balances on them can be moved to new addresses. This would be like a combination check/card. ATMs and cash registers can be adapted to even print new private keys to reload the check/card and send a backup to the online wallet.

[edit] Actually, I don't like the idea of paper either. Some sort of non-magnetic mechanical device to form QR codes would be better.
[edit 2] Memory metal would work for this. The code can be stamped and erased with heat.

Quote from: Phinnaeus Gage on December 09, 2011, 05:08:01 AM

I've been referring to these as "Pay Me" cards, since they basically perform the exact opposite duty of a credit card. (Probably not the best term, but I sort of copied that from a sci-fi TV show I was watching that referred to ID as a Show Me card.)

Instead of being used to give money, you use them to receive a payment. Hand your card to someone, he scans it with a mobile device, and then transfers coins to your account. You could do the same with a cell phone generated QR code, but a card eliminates the need to hand a potential stranger your valuable and rather personal mobile device.

The concept of pulling funds from an account, as is done with basically all modern banking and credit cards, is one of the most fundamental ways the entire banking system is flawed. It will take a little change in thinking to get used to this reversal in how funds are transferred, but we'll all be much better off in the end.

By the way, I can have your card printed for you at www.paymyaddress.com. I do also offer a 20% commission on sales from contributed designs. So far, the best sellers have been my original design and design #5 (the one with the Casascius coin background).

Quote from: BradZimdack on December 09, 2011, 09:32:02 PM

Quote from: Phinnaeus Gage on December 09, 2011, 05:08:01 AM

Sure I'd be happy to submit some designs. Is there something different I should change or add?

I'd like to get with that whole "credit" or "debit" card idea, but it seems like a costly investment. I thought of adding a barcode for POS systems, but I'll see what you think.

Quote from: bwagner on December 10, 2011, 12:42:42 AM

What does the card do? How does it work? Can you give us a simple use case? Is it a "Pay Me" card that just has my public information on it so others can pay me or are you trying to figure out a way to use it to pay others and buy things with it (like the current fiat money denominated credit and debit cards)?

What is your vision here?

I think people have found valid solutions to pay with bitcoins, but not a perfected.

QR codes have finally got more popular up here in Canada, but there are a few flaws with them.

- The camera needs to be decent, which tends to be on smartphones
- A "app" needs to be developed to pay with bitcoins which can be a little security hazard
- The QR code has to be big enough but small enough so it's easy to scan
- The "app" needs to made well to read the QR codes, I've used a few on Windows Mobile, one was great and the rest failed to even the code in the same environment.
- QR codes seem to be a "work around" solution if you get what I mean.

My vision is that you would be able to go to any store and this happens:

Cashier: "How do you want to pay for this?"
You: "Bitcoins please"
Cashier: "Sure, just swipe your card."

Being able to do it would make BTC very popular, it would have some of the lowest fees in history, and almost everyone would be able to take them. The setup costs, and usage costs would also be much lower.

The only real problem is the initial investment for the cards. I mean the real ones, signature panel, stamped numbers and magnetic strip. Costs about $200+ USD for about 50 I think.

Someone may come along and say "OMG! HE'S GOING TO MESS THE WHOLE MARKET UP!" - This is not my point.

Someone will have to do the payments, and I want to stay away from those dirty banks ;). A simple program that I could design and make would perform all the tasks to transfer bitcoins for almost no fee (and side note, I'm working on a pay/transfer via url thing as well, eg. btc:\\pay\myaddress).

This is where I'd like to see bitcoins go, because right now they are only practical for internet usage, and a one off smartphone transfer via QR code. Magnetic swipe cards would be fast and easy. We could even go to RFID tags, but it's another attack surface I think it would be fairly reasonable to avoid.

Quote from: MysteryMiner on December 10, 2011, 04:05:59 AM

Quote from: cbeast on December 09, 2011, 08:33:45 PM

A major problem with magnetic strips is that they are easily erased.

Partially wrong. HiCo magnetic strips are really sturdy. I tried to erase credit card from year 1998 with HiCo magstripe on it. I rubbed it against permanent magnet pulled from old radio loudspeaker. The same magnet is able to damage audio tape and sometimes it can damage standard High Density floppy discs. The credit card worked without any errors in my MSR-206 reader.

P.S. Magstripe readers are much cheaper and simpler devices than optical recognition systems needed for QR codes.

Good to know. OK then. Casascius and others will have a working POS soon that we can use with a real Bitcoin debit card. I was under the impression that QR codes were the new thing. I guess they are best used for writing secure checks.

Quote from: MysteryMiner on December 10, 2011, 05:55:23 PM

There is no need for stamped letters. The stamped letters on credit cards are legacy from earlier days of credit cards. Today most debit cards in europe (Visa Electron and Maestro) have only imprinted numbers.

There is no need for extra items on Bitcoin cards, only the magstripe is needed. They can be very cheap in bulk. In opposite to credit cards, Bitcoin cards have no need to be protected by card design and hidden UV texts and similar. You can forge a fake credit card, but You can't make a fake Bitcoin.

And how much info needs to be stored on the cards? Will they fit into ISO specified tracks?

I wouldn't think it would be too much. I've forgotten the format since last week when I looked at it, but Wikipedia always helps :).

I looked and it seemed that the ISO/IEC 7813 standard would work:

Code:

Track 1

The Track 1 structure is specified as:

    STX : Start sentinel "%"
    FC : Format code "B" (The format described here. Format "A" is reserved for proprietary use.)
    PAN : Primary Account Number, up to 19 digits
    FS : Separator "^"
    NM : Name, 2 to 26 characters (including separators, where appropriate, between surname, first name etc.)
    FS : Separator "^"
    ED : Expiration data, 4 digits or "^"
    SC : Service code, 3 digits or "^"
    DD : Discretionary data, balance of characters
    ETX : End sentinel "?"
    LRC : Longitudinal redundancy check, calculated according to ISO/IEC 7811-2

The maximum record length is 79 alphanumeric characters.
Track 2

The Track 2 structure is specified as:

    STX : Start sentinel ";"
    PAN : Primary Account Number, up to 19 digits, as defined in ISO/IEC 7812-1
    FS : Separator "="
    ED : Expiration date, YYMM or "=" if not present
    SC : Service code, 3 digits or "=" if not present
    DD : Discretionary data, balance of available digits
    ETX : End sentinel "?"
    LRC : Longitudinal redundancy check, calculated according to ISO/IEC 7811-2

The maximum record length is 40 numeric digits.

Of course it would need to be changed, so here's what I thought:

Code:

Track 1

The Track 1 structure is specified as:

    STX : Start sentinel "%"
    FC : Format code "B" (The format described here. Format "A" is reserved for proprietary use.)
    PAN : 0000000000000000000 (Translation account number, where the service would convert this to the actual place to take from)
    FS : Separator "^"
    NM : DarK Stealth (The card holder for ID checks)
    FS : Separator "^"
    ED : ^ (None, this card should last a life time)
    SC : ^ (No service code)
    DD : Discretionary data, balance of characters
    ETX : End sentinel "?"
    LRC : Longitudinal redundancy check, calculated according to ISO/IEC 7811-2

The maximum record length is 79 alphanumeric characters.
Track 2

The Track 2 structure is specified as:

    STX : Start sentinel ";"
    PAN : 0000000000000000000 (Translation account number, where the service would convert this to the actual place to take from)
    FS : Separator "="
    ED : = (None, this card should last a life time)
    SC : = (None, this card should last a life time)
    DD : Discretionary data, balance of available digits
    ETX : End sentinel "?"
    LRC : Longitudinal redundancy check, calculated according to ISO/IEC 7811-2

The maximum record length is 40 numeric digits.

Thinking about it, we could really just have a magnetic stripe, as it would be cheaper.

I need to know what data MUST be on the magstripe tracks. The ISO format for contents probably is not needed as it may not fit the data. It's designed for bank accounts.

Track1: Private key to sign transactions. Some checksum digit at the end
Track2: receiving address. The starting character can be 1
Track3: Other??? No need for name of cardholder or date of expiry. The bitcoin must be anonymous and the coins will not expire. When card wears out, it can be copied to new one.

When exact needed data will known, I will try to write that on standard loco card.

The drawback is that coins can be spent with single private key must be recieved to the same address. I'm right? This means the bitcoin receiving address can be linked to single cardholder.

Quote from: BradZimdack on December 09, 2011, 09:32:02 PM

Interesting! Perhaps relevant is that this is the way checks work in Europe. A check is not something you take to the bank to deposit, it is something you take to the bank to pay. My utilities send me a check every month.

Quote from: BradZimdack on December 09, 2011, 09:32:02 PM

I've been referring to these as "Pay Me" cards, since they basically perform the exact opposite duty of a credit card.

...

Instead of being used to give money, you use them to receive a payment. Hand your card to someone, he scans it with a mobile device, and then transfers coins to your account.

So you'd want a Pay Me QR code posted by the merchant. Scan it with your device, your app feeds BitCoin an address and, ideally, a total cost. It then sends the BTC automatically once you've confirmed the transaction, and once the merchant has gotten sufficient verification from the network the transaction is successfully completed.

More optimally, merchants would generate a unique per-transaction QR code. This would enable correct pricing and easy verification of which transaction it was that had just processed. Per-transaction QRs could be generated on receipt paper (pre-ceipts? QR billing?) or perhaps even just generated on a screen to be scanned with the customer's mobile device.

So what you'd seem to actually want is an app. Easier and more cost-effective than physical materials anyway.

Be well,

- Satori

Quote from: MysteryMiner on December 23, 2011, 03:07:15 PM

Having a private key would make it easy to steal. I wonder if part of a private key could be had, and the user would have to enter another part of it kind of like a PIN.

Quote from: Satori on January 16, 2012, 09:32:07 AM

More optimally, merchants would generate a unique per-transaction QR code. This would enable correct pricing and easy verification of which transaction it was that had just processed. Per-transaction QRs could be generated on receipt paper (pre-ceipts? QR billing?) or perhaps even just generated on a screen to be scanned with the customer's mobile device.

This would be the end game. Using either QR codes and/or NFC the payment terminal (same one you click credit or debit) would provide data on the entire transaction.

This requires acceptance of a standard format which would have at least amount, and payment address but could also provide optional information which could be used by more advanced wallets like transaction time, merchant name, products purchased, digital signature of entire receipt.

Users receives data (either NFC or by scanning QR code) and then confirms outgoing transaction in smart phone. Cashier's terminal indicates payment successful just like w/ credit card.

To be "green" potential no paper receipt is needed. The data sent to wallet could be used as a receipt and provides advantages of security (receipt can't be faked for returns due to digital signature), integration into money management products (imagine Quickbooks for Bitcoin :) ), and the ability to make backups of receipts (no more lost receipts).

Quote from: dark_st3alth on December 09, 2011, 05:03:16 AM

Bitcoin Magnetic Card Designs by DarK_St3alth is licensed under a Creative Commons Attribution-NonCommercial-NoDerivs 3.0 Unported License.

Um, why such a restrictive license. This is an image for a credit card and all derivatives of it are not allowed to be used on a commercial product... so it cannot be used then? Credit cards are commercial products. Why not just say, "I own the copyright"

Please, if you want people to use your stuff, just use the WTFPL license. It is certainly less confusing than all that creative commons nonsense.

http://sam.zoy.org/wtfpl/

Code:

           DO WHAT THE FUCK YOU WANT TO PUBLIC LICENSE
                   Version 2, December 2004

Copyright (C) 2004 Sam Hocevar <sam@hocevar.net>

Everyone is permitted to copy and distribute verbatim or modified
copies of this license document, and changing it is allowed as long
as the name is changed.

           DO WHAT THE FUCK YOU WANT TO PUBLIC LICENSE
  TERMS AND CONDITIONS FOR COPYING, DISTRIBUTION AND MODIFICATION

 0. You just DO WHAT THE FUCK YOU WANT TO.

If you don't want people to use your stuff, then just say so.

Quote from: DeathAndTaxes on January 16, 2012, 02:49:58 PM

For this verbose data, I would simply transmit a URL that would allow the customer to access the transaction online. The transmitted URL would also be time-sensitive to allow for re-use of QR codes for subsequent transactions by the same merchant. Ideally the client's app would load the temporary URL, access the transaction record to retrieve the verbose data, and then one of the fields would be a more permanent URL.

Many free URL shorteners can do this part easily, and there's even a QR generation module for Drupal (http://drupal.org/project/qr_codes). No problem there. Easy to Drupal up a site with the QR codes, loadable and displayable on the merchant's smart phone.

Acceptance of a standard format can be made easy through user adoption; attempting to get something like this established through the providers of those credit-or-debit payment systems may be difficult, and defeat BitCoin's free-as-in-beer strong point. With just apps for mobile devices, one for customers and one for merchants, the public could and would adopt it easily; all they'd need would be the mobile devices they already have, and the app. Result: Adoption of the above-mentioned standard format, and increasing abandonment of banks and credit card companies. I consider this optimal.

Rather than attempt to persuade mainstream terminal providers to adopt an as-yet-unused protocol, it seems preferable to just let users adopt it freely out of convenience. At that point, terminal providers would just look silly for as long as they refused to catch up.

We may be about ready to crowdsource funding to hire app coders for this open-source project. Anything else?

Quote from: DeathAndTaxes on January 23, 2012, 05:23:22 PM

Quote from: cbeast on January 23, 2012, 05:20:33 PM

Quote from: robkohr on January 23, 2012, 04:54:21 PM

People, the cell phone is the cc of the future. Credit cards will be moving to it, and bitcoins are already there. The apps need a little work to make them faster at accepting 0-confirm transactions, and maybe a little better for storefront accounting, but really, this is a solved problem.

Until they invent a battery-free mobile, plastic will remain.

Except a "debit/credit" bitcoin card won't be magnetic. At a minimum it likely will need to be a smartcard and preferably one with a display, keypad, and yes battery.

So what do you do if on some dark stormy night in the country you run out of gas and your battery goes dead? The unmanned gas station takes credit cards, but you only have a dead Bitcoin Card battery. Will you spend the night in that cabin in the woods while your batter charges?

Quote from: cbeast on January 23, 2012, 05:42:56 PM

Quote from: DeathAndTaxes on January 23, 2012, 05:23:22 PM

Quote from: cbeast on January 23, 2012, 05:20:33 PM

Quote from: robkohr on January 23, 2012, 04:54:21 PM

Until they invent a battery-free mobile, plastic will remain.

Except a "debit/credit" bitcoin card won't be magnetic. At a minimum it likely will need to be a smartcard and preferably one with a display, keypad, and yes battery.

What rechargeable battery? Batteries in smartcards aren't rechargable or replaceable. They are simply designed to last the life of the card. I am just pointing out the way that Bitcoin works (private keys) means a Bitcoin card you can swipe is a non-starter. Maybe systems built on TOP of Bitcoin but not Bitcoin itself. I mean what exactly are you going to put on the swipe? Your private key? So all your wallet funds can be stolen by anyone you purchase something from?

The reality is a BITCOIN mangentic swiped card will never happen. Now some private network built on top of Bitcoin (think VISA Bitcoin)? Sure but not Bitcoin itself. Not unless you think the world will work based on trust and unicorns.

The only SECURELY way to have a Bitcoin POS system is where your device (phone or smartcard) does the SIGNING and the only thing the merchant gets is the signed transaction.

So something like:
1) you owe 1.25 BTC
2) you insert smartcard
3) using a standardized protcol the POS system gives the smartcard the amount and address to pay
4) your smartcard uses its onboard display to show the amount being paid
5) as a security precaution you now enter your PIN on the keypad on the smartcard.
6) the smartcard signs a transactions for the amount and address provided and gives it to the POS system
7) the chashier thanks you, gives you a receipt and you go on your way.

Yes the technology does exist.
http://cdn.slashgear.com/wp-content/uploads/2010/06/mastercard_smart_cards-540x349.jpg

Any system where you give the private keys to untrusted parties is worthless. It will never be adopted because it is trivial to rob someone of all of their assets.

Quote from: DeathAndTaxes on January 23, 2012, 05:49:01 PM

Quote from: cbeast on January 23, 2012, 05:42:56 PM

Quote from: DeathAndTaxes on January 23, 2012, 05:23:22 PM

Quote from: cbeast on January 23, 2012, 05:20:33 PM

Quote from: robkohr on January 23, 2012, 04:54:21 PM

Until they invent a battery-free mobile, plastic will remain.

Except a "debit/credit" bitcoin card won't be magnetic. At a minimum it likely will need to be a smartcard and preferably one with a display, keypad, and yes battery.

What rechargeable battery? Batteries in smartcards aren't rechargable or replaceable. They are simply designed to last the life of the card. I am just pointing out the way that Bitcoin works (private keys) means a Bitcoin card you can swipe is a non-starter. Maybe systems built on TOP of Bitcoin but not Bitcoin itself. I mean what exactly are you going to put on the swipe? Your private key? So all your wallet funds can be stolen by anyone you purchase something from?

The reality is a BITCOIN mangentic swiped card will never happen. Now some private network built on top of Bitcoin (think VISA Bitcoin)? Sure but not Bitcoin itself. Not unless you think the world will work based on trust and unicorns.

The only SECURELY way to have a Bitcoin POS system is where your device (phone or smartcard) does the SIGNING and the only thing the merchant gets is the signed transaction.

So something like:
1) you owe 1.25 BTC
2) you insert smartcard
3) using a standardized protcol the POS system gives the smartcard the amount and address to pay
4) your smartcard uses its onboard display to show the amount being paid
5) as a security precaution you now enter your PIN on the keypad on the smartcard.
6) the smartcard signs a transactions for the amount and address provided and gives it to the POS system
7) the chashier thanks you, gives you a receipt and you go on your way.

Any system where you give the private keys to untrusted parties is worthless. It will never be adopted because it is trivial to rob someone of all of their assets.

I live in the USA. We don't have these advanced systems yet, though wikipedia explains that every other nation does. Fascinating.

A card that can do the signing of a transaction could be powered by the POS device. Here is the flow:

*Plug card into pos device
*Send public address to pos
*pos assembles all the parts of the transaction and sends the transaction to the card
*card displays transaction on mini screen and has a button to accept
*transaction is signed and sent back to pos

I think something like this could be built on a usb powered Arduino nano device with some clever coding.
http://arduino.cc/en/Guide/ArduinoNano

----

Actually, ignore all of the above.

"So what do you do if on some dark stormy night in the country you run out of gas and your battery goes dead? "

*Do all transactions need internet access - YES
*Does your POS most likely have a usb port to charge your phone from - YES

Then you don't need anything but your phone still. If the merchant needs power himself, as well as internet access, then you don't have a power problem for your phone (most likely).

The only thing that works in offline mode is physical bitcoins.

Quote from: robkohr on January 24, 2012, 12:11:58 AM

Actually physical bitcoins dont work either. The only way they could work is if it cost more to produce a fake one than it was worth... Which means anyone manufacturibg such a thing could never make profit.

Offline transactions are possible with highly encrypted hardware and escrow accounts locked for 24 hours etc on a central authority

Quote from: BradZimdack on December 09, 2011, 09:32:02 PM

Quote from: Phinnaeus Gage on December 09, 2011, 05:08:01 AM

Quote from: Satori on January 16, 2012, 09:32:07 AM

Quote from: BradZimdack on December 09, 2011, 09:32:02 PM

This is exactly what's been implemented on Android.

Article: Bitcoin payments go mobile with Bitcoin for Android (http://thenextweb.com/mobile/2011/07/06/bitcoin-payments-go-mobile-with-bitcoin-for-android/)

Bitcoin Forum

Bitcoin => Bitcoin Discussion => Topic started by: dark_st3alth on December 09, 2011, 05:03:16 AM