Introducing Bitbills!

[llama]

Check it out, after months of effort I'm proud to announce I've released my new bitcoin product: Bitbills!

www.bitbills.com

Bitbills are the first physical incarnation of bitcoins, and I'm selling them starting now! Let me know what you guys think, and if you have any questions or comments!

[BCEmporium]

WOW! Quite a nice job taken by the pictures.

Me and Atlas were talking about it some time ago in the forum but I'd never expect to see them to come real so soon.
Here is the sample I used to show Atlas my idea (based on his ideas):



Congrats.

[Jeffpod]

Nice Job on the BitBills.
Freaking Awesome!

[caveden]

Quite cool! Congratulations.

It's a nice geek gift card this one.

Suggestion: upload videos showing how to redeem a card, as well as how to verify authenticity.

[kseistrup]

www.bitbills.com

Sweet, good luck!  

Cheers,

[Mahkul]

This is amazing man! Congratulations!

[Anonymous]

This is awesome.

Im no longer going to use an online wallet to store coins Im using these. There is just something visceral about holding a physical representation:)

[ColdHardMetal]

That's pretty neat.

[ploum]

If I understand that well, it means that you hide a code behind a sticker. With the code, you can get the bitcoins on your virtual wallet.

So, my questions are:

1) How do you guarantee the holder of the card that the coins are still available? Currently, we have to trust you (the emitter) *and* the fact that the sticker has not been removed, which looks a bit gross (it shouldn't be that hard to replace a sticker with another one).

2) How could the user be sure that the card was emitted by you? I mean, I could print a bunch of cards with QR code and stickers, sell them for 1 or 5btc. The holder will exchange them and a the time someone try to cash them, nobody will be able to trace the card to me.


The idea is interesting but could you elaborate on those two points?

[Leandro César]

Very good!

Congratulations!

L.

[caveden]

1) How do you guarantee the holder of the card that the coins are still available? Currently, we have to trust you (the emitter) *and* the fact that the sticker has not been removed, which looks a bit gross (it shouldn't be that hard to replace a sticker with another one).

Well, you can always look the block chain too. If the money remains in the address, you should see at block explorer for example. But yeah, on offline transactions, you have to trust it's not a fake card.

2) How could the user be sure that the card was emitted by you? I mean, I could print a bunch of cards with QR code and stickers, sell them for 1 or 5btc. The holder will exchange them and a the time someone try to cash them, nobody will be able to trace the card to me.

I think he expects the holograms to be enough for it. And, well, it's pretty much the same thing for state money bills...

[llama]

If I understand that well, it means that you hide a code behind a sticker. With the code, you can get the bitcoins on your virtual wallet.

So, my questions are:

1) How do you guarantee the holder of the card that the coins are still available? Currently, we have to trust you (the emitter) *and* the fact that the sticker has not been removed, which looks a bit gross (it shouldn't be that hard to replace a sticker with another one).

2) How could the user be sure that the card was emitted by you? I mean, I could print a bunch of cards with QR code and stickers, sell them for 1 or 5btc. The holder will exchange them and a the time someone try to cash them, nobody will be able to trace the card to me.


The idea is interesting but could you elaborate on those two points?

Good questions. I've grouped the security concerns into three classes: Counterfeiting, tampering, and source-trust.

Source-trust means that you have to trust me, and I haven't thought of a good way around that. I promise that I put the bitcoins on the cards, delete the private keys, and use a secured manufacturing process. My hope is that as people begin buying, using, and redeeming Bitbills, they will form a trusting relationship with me the same way you might have a trusting relationship with MtGox and other companies.

Counterfeiting is the problem of others copying our cards and passing them off as real (presumably without even including the private key). Our cards are fundamentally hard to manufacture. When handling Bitbills, always check that the design matches the one shown on our website to make sure it's an authentic card. We use holograms that are very difficult to replicate. As our business grows, we plan to implement more and more security features.

Tampering is the problem of people extracting the private key without it being visible. We put the private key actually inside of the layers of plastic, so it's not just a simple matter of carefully peeling off a sticker or anything. The hologram is directly on top of the private key, also within the plastic. Even if it is somehow covertly extracted (once you see one of these, you'll see just how impossible that seems), the hologram destructs when removed.

We're working hard to make sure Bitbills are as sound as bitcoins themselves (if not better, since they clear instantly). But remember, like all the best stuff, they are BETA

[ploum]

Good questions. I've grouped the security concerns into three classes: Counterfeiting, tampering, and source-trust.

Good, those are indeed the 3 main aspects I foresee.

Source-trust means that you have to trust me […]

Let assume that for granted for now

Counterfeiting is the problem of others copying our cards and passing them off as real (presumably without even including the private key). Our cards are fundamentally hard to manufacture. When handling Bitbills, always check that the design matches the one shown on our website to make sure it's an authentic card. We use holograms that are very difficult to replicate. As our business grows, we plan to implement more and more security features.

If you were able to produce those cards yourself, do you think it would be hard for anybody to produce the same? I don't think you invested thousands and thousands of money in that process. So, as long as you can do it, other people can. They only have to be able to do it for a value of less than the facial value.

Also, introducing new security features that cannot be copied (looks hard) is worthless if you already have cards in circulation. People will simply use those cards.

Tampering is the problem of people extracting the private key without it being visible. We put the private key actually inside of the layers of plastic, so it's not just a simple matter of carefully peeling off a sticker or anything. The hologram is directly on top of the private key, also within the plastic. Even if it is somehow covertly extracted (once you see one of these, you'll see just how impossible that seems), the hologram destructs when removed.

Let's take that for granted. After all, lotteries are doing that everyday.

We're working hard to make sure Bitbills are as sound as bitcoins themselves (if not better, since they clear instantly). But remember, like all the best stuff, they are BETA

I hope I don't sound to harsh. I'm trying to be constructive. All I know is that I would gladly accept to be paid in BTC for anything but I'm still unsure about accepting a card like yours.

By the way: what is your business model? How would you gain money from a 5BTC card that I buy 5BTC (presumably?). (I see one potential business: selling to an higher rate against dollars but I don't know which is yours).

[vuce]

This is awesome, but seems a bit crude, too much work to get the actual coins out and way to thick to fit many in a wallet. How about bills like lottery tickets, when one has to scratch off the top layer? I imagine those would be cheaper to make also?

[Cusipzzz]

I'm as skeptical as anyone about the security/trust issue involved (double-spend card attacks indeed) - but I think you've done great work so far, really impressive. Look forward to seeing future use/enhancements.

[SgtSpike]

Isn't the tampering issue taken care of with the QR code on the back that allows you to check the bitcoin address's balance?  If there's no balance, don't accept it...

Regarding counterfeiting...  I'm not sure if this already happens, but if not, it should.  The balance should be checked THROUGH the official BitBills website.  If BitBills did not produce the bitcoin address on the card, it should be shown as an invalid/counterfeit card.  If BitBills DID produce the bitcoin address on the card, then it should validate the address and show you the balance.  Cards should be invalidated once ANY transaction is made from the address, as that means that the private key has been revealed to someone.

[FreeMoney]

Looks very cool.

A couple thoughts.

Checking the balance doesn't mean much since anyone clever will wait until after the sale to move the coins and you won't be rushing out to destroy the bill normally.

Even if it is virtually impossible to make a bill that could fool you, it won't be nearly as hard to fool someone who hasn't handled them themselves. This is more of a problem in the beginning, but it could recur as you change the design.

The prices seem reasonable. Will they get even lower if you can scale up? Do you figure people will trade them at face value or retail? Smaller denominations coming soon?

[SgtSpike]

Looks very cool.

A couple thoughts.

Checking the balance doesn't mean much since anyone clever will wait until after the sale to move the coins and you won't be rushing out to destroy the bill normally.

Even if it is virtually impossible to make a bill that could fool you, it won't be nearly as hard to fool someone who hasn't handled them themselves. This is more of a problem in the beginning, but it could recur as you change the design.

The prices seem reasonable. Will they get even lower if you can scale up? Do you figure people will trade them at face value or retail? Smaller denominations coming soon?

Good point about the balance checking.  However, if the card hasn't been destroyed, how would the person obtain the private key?

The only way I see a scam working is if someone made an exact replica of an existing card with the same bitcoin address, destroyed the real one to get the private key, then sold the fake one before transacting the bitcoins out of the account.  That's a lot of work to go through for ~$35 max.

[FreeMoney]

  That's a lot of work to go through for ~$35 max.

Already there are $75 cards and this will only go up. It might cost thousands to find a good way, but then each time will be cheap. I'm thinking special camera or something.

[SgtSpike]

  That's a lot of work to go through for ~$35 max.

Already there are $75 cards and this will only go up. It might cost thousands to find a good way, but then each time will be cheap. I'm thinking special camera or something.

Ah, my bad.  I thought they went up to 10BTC max.

Well, I suppose it's possible that a counterfeiting operation could disrupt bitbills.  It'd have to be very organized...

Here's another idea.  Have a series of pin #'s on the back of the card, all of them covered with the same stuff they cover scratch-it's in.  Have maybe 25 of them or something.  If you are worried about the validity of the card, you can scan the QR code, it shows you the balance of the bitcoins on the account, then you scratch off a new pin # to double-check that it is a legitimate card.  If a pin # has already been checked, it won't show as legitimate.

Hmmm, actually, that probably wouldn't work.  If the counterfeiting operation already had the original, they could just scratch off all of the pins on the original, add them to the new card, and then rescratch up to the pins that had been used on the original.

Uhmmmm... I'm out of ideas.  :p