Keypair cards now available through Bitbills!

[SgtSpike]

So, lemme get this straight.  Your customers have to trust you with their private key?

Or just the bitcoin address, if all they want is the reference card.

[enmaku]

I have to say the metal engraving is a nice touch, but wouldn't a laminated card (like a credit card) work just as well and be a lot cheaper?

I like these for the same reason we began our civilization with gold and silver currencies: durability. Metal engraved cards will work exactly the same as laminated cards, but will likely last much longer.

Other things I'd like to see along these lines:

• Punch the QR code all the way through thus creating metal bitcoin punchcards, for maximum durability and a retro look/feel
• QR codes engraved onto round metal blanks - actual bitCOINS
• Bitcoin QR code jewelry?
• Forget the card/bill/coin form factor (it's so 20th century), bleed the QR codes all the way to the edge and make tiny rectangular metal currency - I'm imagining gold-pressed latinum for some reason
• For the incredibly wealthy, take my QR coin idea and do it with actual gold or silver - combining a physical AND digital commodity

The possibilities are endless!

[nazgulnarsil]

Do want.

don't trust anyone with a private code, but a reference card would be neat.  Any ideas on price (ballpark, under $20?)

[spruce]

For a savings wallet QR code you could also have it tattooed on.

Since you have to really spend it all once it's been opened, thus rendering the tat non-functional, that would be a good incentive not to spend it!

[LightRider]

Really interesting. An upgrade from the bitbill concept in my opinion.

[SgtSpike]

For a savings wallet QR code you could also have it tattooed on.

Since you have to really spend it all once it's been opened, thus rendering the tat non-functional, that would be a good incentive not to spend it!

Why would you have to spend it all once it's been opened?

Just tattoo your bitcoin address, then anyone can scan your skin to send money to you!

[FuzzyCoins]

If this is a cute way of publishing your public address as a way to receive BTC then it is cute, maybe even classy.

If it is supposed to be a way to send money, then it is useless (or at least insecure). If the private key is printed on it (as a set of numbers or QR code or whatever) then all I have to do to steal the BTC is look at it, maybe even from a distance. I can use a camera with a telephoto lens and take a picture of you holding your card. As soon as I do this I can spend your BTC.

If you give me one of these as payments for something, I have to run the transaction then and there to make sure the BTC hasn't already been spent. It is not a way to perform a BTC transaction offline. It is not a way to securely hold BTC.

I suppose you can take the private card and keep it out of sight (literally), but why put it on a wallet size card if you aren't going to carry it around?

[spruce]

For a savings wallet QR code you could also have it tattooed on.

Since you have to really spend it all once it's been opened, thus rendering the tat non-functional, that would be a good incentive not to spend it!

Why would you have to spend it all once it's been opened?

Just tattoo your bitcoin address, then anyone can scan your skin to send money to you!

I would do it for safety. I guess it depends what software with what security is available at the time it happens. I like the idea of "one-time" savings wallets that you can send to as often as you want but then only expose the private key once. If you're happy with your crypto-nerd powers then it's probably not necessary, but being a crypto-weeny myself I'll settle for something like Casascius's paper wallet key-pairs, rather than having to deal with the change into a new address and so forth.

I don't mind dealing with a small day-to-day spending wallet client on my regular computer, but a savings wallet and arcane (for me) crypto precautions? Nope, sorry.

[phorensic]

Noitev, how much acid were you on when you made your signature?

[Ryland R. Taylor-Almanza]

I can't wait for you to start selling these!

[Kermee]

Would purchase at least two.  What a wonderful way of 're-investing' into BTC's future with your earnings.

Cheers,
Kermee

[jonathan]

aww, sweet!

[SgtSpike]

For a savings wallet QR code you could also have it tattooed on.

Since you have to really spend it all once it's been opened, thus rendering the tat non-functional, that would be a good incentive not to spend it!

Why would you have to spend it all once it's been opened?

Just tattoo your bitcoin address, then anyone can scan your skin to send money to you!

I would do it for safety. I guess it depends what software with what security is available at the time it happens. I like the idea of "one-time" savings wallets that you can send to as often as you want but then only expose the private key once. If you're happy with your crypto-nerd powers then it's probably not necessary, but being a crypto-weeny myself I'll settle for something like Casascius's paper wallet key-pairs, rather than having to deal with the change into a new address and so forth.

I don't mind dealing with a small day-to-day spending wallet client on my regular computer, but a savings wallet and arcane (for me) crypto precautions? Nope, sorry.

I still don't get it.

You'd never have to expose any private keys (beyond having them in your wallet).  Just pick an address that your wallet generates, then make a QR code out of it and use that for a tattoo.

[Noitev]

Noitev, how much acid were you on when you made your signature?

obviously not enough.

Don hertzfeldt is amazing

[Noitev]

For a savings wallet QR code you could also have it tattooed on.

Since you have to really spend it all once it's been opened, thus rendering the tat non-functional, that would be a good incentive not to spend it!

Why would you have to spend it all once it's been opened?

Just tattoo your bitcoin address, then anyone can scan your skin to send money to you!

I would do it for safety. I guess it depends what software with what security is available at the time it happens. I like the idea of "one-time" savings wallets that you can send to as often as you want but then only expose the private key once. If you're happy with your crypto-nerd powers then it's probably not necessary, but being a crypto-weeny myself I'll settle for something like Casascius's paper wallet key-pairs, rather than having to deal with the change into a new address and so forth.

I don't mind dealing with a small day-to-day spending wallet client on my regular computer, but a savings wallet and arcane (for me) crypto precautions? Nope, sorry.

I still don't get it.

You'd never have to expose any private keys (beyond having them in your wallet).  Just pick an address that your wallet generates, then make a QR code out of it and use that for a tattoo.

I think the biggest problem, especially after the recent theft of 25k btc, is that people dont trust their computers, the pairs help because they wont be linked to a computer and so any funds on them are safe until redeemed, I suppose you need to trust I won't hijack it, but I've been in btc for a while and really have no interest in theft and want to see btc take off. I got scammed out of 120 btc when they cost less and really dont want to see that happen. all of the keypairs will be made offline and deleted.

[SgtSpike]

For a savings wallet QR code you could also have it tattooed on.

Since you have to really spend it all once it's been opened, thus rendering the tat non-functional, that would be a good incentive not to spend it!

Why would you have to spend it all once it's been opened?

Just tattoo your bitcoin address, then anyone can scan your skin to send money to you!

I would do it for safety. I guess it depends what software with what security is available at the time it happens. I like the idea of "one-time" savings wallets that you can send to as often as you want but then only expose the private key once. If you're happy with your crypto-nerd powers then it's probably not necessary, but being a crypto-weeny myself I'll settle for something like Casascius's paper wallet key-pairs, rather than having to deal with the change into a new address and so forth.

I don't mind dealing with a small day-to-day spending wallet client on my regular computer, but a savings wallet and arcane (for me) crypto precautions? Nope, sorry.

I still don't get it.

You'd never have to expose any private keys (beyond having them in your wallet).  Just pick an address that your wallet generates, then make a QR code out of it and use that for a tattoo.

I think the biggest problem, especially after the recent theft of 25k btc, is that people dont trust their computers, the pairs help because they wont be linked to a computer and so any funds on them are safe until redeemed, I suppose you need to trust I won't hijack it, but I've been in btc for a while and really have no interest in theft and want to see btc take off. I got scammed out of 120 btc when they cost less and really dont want to see that happen. all of the keypairs will be made offline and deleted.

True enough.  I suppose it's easier to trust a single person than trust that your computer will be safe from hax forever.

I do like the metal engraving idea, I just think it might be too expensive for most people.  But I'm anxious to see how they turn out. 

[Noitev]

For a savings wallet QR code you could also have it tattooed on.

Since you have to really spend it all once it's been opened, thus rendering the tat non-functional, that would be a good incentive not to spend it!

Why would you have to spend it all once it's been opened?

Just tattoo your bitcoin address, then anyone can scan your skin to send money to you!

I would do it for safety. I guess it depends what software with what security is available at the time it happens. I like the idea of "one-time" savings wallets that you can send to as often as you want but then only expose the private key once. If you're happy with your crypto-nerd powers then it's probably not necessary, but being a crypto-weeny myself I'll settle for something like Casascius's paper wallet key-pairs, rather than having to deal with the change into a new address and so forth.

I don't mind dealing with a small day-to-day spending wallet client on my regular computer, but a savings wallet and arcane (for me) crypto precautions? Nope, sorry.

I still don't get it.

You'd never have to expose any private keys (beyond having them in your wallet).  Just pick an address that your wallet generates, then make a QR code out of it and use that for a tattoo.

I think the biggest problem, especially after the recent theft of 25k btc, is that people dont trust their computers, the pairs help because they wont be linked to a computer and so any funds on them are safe until redeemed, I suppose you need to trust I won't hijack it, but I've been in btc for a while and really have no interest in theft and want to see btc take off. I got scammed out of 120 btc when they cost less and really dont want to see that happen. all of the keypairs will be made offline and deleted.

True enough.  I suppose it's easier to trust a single person than trust that your computer will be safe from hax forever.

I do like the metal engraving idea, I just think it might be too expensive for most people.  But I'm anxious to see how they turn out. 

It really shouldn't cost too much

[phillipsjk]

Would the wax or plastic over the private key be tamper-evident? What happens when I shine infra-red light on it?

I think the engraving would be too durable and clear to securely store the private key.

[netrin]

I still don't get it.

You'd never have to expose any private keys (beyond having them in your wallet).  Just pick an address that your wallet generates, then make a QR code out of it and use that for a tattoo.

It would be nice if our wallets were separated individually into the addresses and the private keys in digital form. The OP is engraving the private key (minimal wallet), hidden under tamper-evident gunk, with a lovely address line in plaintext and luxurious QR.

(I pondered similar ideas for Father's Day, but...)

Why?

[Noitev]

Would the wax or plastic over the private key be tamper-evident? What happens when I shine infra-red light on it?

I think the engraving would be too durable and clear to securely store the private key.

I think you guys are missing the message.

The picture is a prototype, the finished product will have 2 linked cards. 1 public and a separate card that's private.