CASASCIUS PHYSICAL BITCOIN - In Stock Now! (pic)

[indio007]

Money is whatever the parties to a contract agree it is. It would be more correct to say it isn't currency.


Still... what's the durability on these suckers?

[1713583415]

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[1713583415]

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[1713583415]

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[casascius]

1 - How does one verify that it was you who made the coin?
2 - How does one verify that there is, indeed 1 bitcoin loaded in without 'destroying' the coin?
3 - Once the bitcoin is redeemed what happens to the coin? (just seems a terrible waste of preciois metal)
(4) Next just a discussion, alot of people are suggesting QR codes. Would using them make any difference? Apart from making it harder?
I love this idea, though! (5) Will you be making coins of smaller amounts?
Many thanks

1 - I chose a hologram with the name Casascius on it, because that would be prohibitively expensive ($thousands) for someone else to duplicate.  And if they're going to go to the effort, they may as well make their own legitimate coins (clearly there's a demand) rather than perpetrating a fraud that would get quickly found out.

2 - Each coin has the first 8 characters of the bitcoin address on it, which is enough for Block Explorer to find it.  When I load bitcoins on coins, the transactions are fairly distinct - lots of outputs of 1 BTC to lots of addresses wrapped into a single transaction.  So if someone were to vanitygen one (the odds of it happening purely at random are 2.2 trillion to 1) you could find the right transaction.

3 - it becomes a piece of metal, not quite as desirable, but still cool nonetheless.

4 - I could probably put together QR codes, but I favor readable codes for several good reasons, the most significant being that most people don't know how to scan them into a program without retyping them anyway (typical joe will scan with his iphone and type into his computer what he sees on the screen, defeating the purpose).  And second, if the code gets torn or damaged, your eyeball will do a much better job of piecing it back together than a phone that will just say it can't read the code.

5 - Probably no smaller amounts.  Maybe bigger amounts (such as 10 or 50 BTC in larger, more ornate coins).  This is fairly time consuming for me as it is, and I fear that demand could outstrip my ability to supply them.  It's hard to want to delegate it, as I can make sure that all of the codes are legible and correct and match the address on the outside, but somebody else might not take that so seriously.

6 - Others have asked about durability.  I don't know yet - haven't had them that long.  The adhesive is quite strong and they will probably resist water just fine, but what would really ruin them is if they sat in your pocket and got jingled around with your keys.  I would treat them as delicate until proven otherwise.  I am experimenting with spraying on a layer of polyacrylate which adds significant protection to the hologram, particularly at the edges, but it will take me several days to really know for sure how that will end up.  Seriously though, I hope somebody copies my idea and does a better job and makes a wash-proof key-proof bullet-proof coin for less.

[Drifter]

This is very cool, and one of the best projects for bitcoin I've seen yet. Thanks for your work and I can't wait to see what happens with your idea in the future.

[Sultan]

1 - How does one verify that it was you who made the coin?
2 - How does one verify that there is, indeed 1 bitcoin loaded in without 'destroying' the coin?
3 - Once the bitcoin is redeemed what happens to the coin? (just seems a terrible waste of preciois metal)
(4) Next just a discussion, alot of people are suggesting QR codes. Would using them make any difference? Apart from making it harder?
I love this idea, though! (5) Will you be making coins of smaller amounts?
Many thanks

1 - I chose a hologram with the name Casascius on it, because that would be prohibitively expensive ($thousands) for someone else to duplicate.  And if they're going to go to the effort, they may as well make their own legitimate coins (clearly there's a demand) rather than perpetrating a fraud that would get quickly found out.

2 - Each coin has the first 8 characters of the bitcoin address on it, which is enough for Block Explorer to find it.  When I load bitcoins on coins, the transactions are fairly distinct - lots of outputs of 1 BTC to lots of addresses wrapped into a single transaction.  So if someone were to vanitygen one (the odds of it happening purely at random are 2.2 trillion to 1) you could find the right transaction.

3 - it becomes a piece of metal, not quite as desirable, but still cool nonetheless.

4 - I could probably put together QR codes, but I favor readable codes for several good reasons, the most significant being that most people don't know how to scan them into a program without retyping them anyway (typical joe will scan with his iphone and type into his computer what he sees on the screen, defeating the purpose).  And second, if the code gets torn or damaged, your eyeball will do a much better job of piecing it back together than a phone that will just say it can't read the code.

5 - Probably no smaller amounts.  Maybe bigger amounts (such as 10 or 50 BTC in larger, more ornate coins).  This is fairly time consuming for me as it is, and I fear that demand could outstrip my ability to supply them.  It's hard to want to delegate it, as I can make sure that all of the codes are legible and correct and match the address on the outside, but somebody else might not take that so seriously.

6 - Others have asked about durability.  I don't know yet - haven't had them that long.  The adhesive is quite strong and they will probably resist water just fine, but what would really ruin them is if they sat in your pocket and got jingled around with your keys.  I would treat them as delicate until proven otherwise.  I am experimenting with spraying on a layer of polyacrylate which adds significant protection to the hologram, particularly at the edges, but it will take me several days to really know for sure how that will end up.  Seriously though, I hope somebody copies my idea and does a better job and makes a wash-proof key-proof bullet-proof coin for less

Thanks for your your prompt reply! Just to continue the discussion further, if I may...

1 - Just to clarify, each of the holograms are exactly the same? If this is the case, I feel this may be a bit of a risk because, agreex, the initial investment in duplicating the pattern will be huge, but if they mass-produce this and put it into 1,000 coins, the criminals would make their money back in no time. My humble suggestion would be to digitally sign each address which could be verified online. That way each hologram is different, although I am not sure if this would incur higher costs.

2 - Forgive me, I am not sure I understand the security feature of "lots of inputs wrapped into one transaction? Could you explain this a little more simply? Surely if I knew the address on the coin I could find out how many bitcoins are assigned to it?


3 - Will you buy spent coins to make new coins?

4 - Wholeheartedly agree with you. Readable is better than QR in this case .

5 - I guess without smaller coins the intention is for the coin not to be used in small trades?

Once again thank you for your quick response!

[ShadowOfHarbringer]

I am a bitcoiner and what is this ?

DO WANT !

[tsupp4]

How many of these coins do you have available / how long does it take to produce them?

[casascius]

How many of these coins do you have available / how long does it take to produce them?

I can knock out maybe 80 to 100 in an hour.  I have plenty of supplies.

[casascius]

PGP-signed list of a portion of addresses I pre-generated for this project (all coins made thus far are within this list).

http://pastebin.com/XebW67V4

[Cory]

Did you send out the first(?) batch?

I can't wait to get mine. They look great!

[BurtW]

This is one of the coolest bitcoin related items I have seen.  Can't wait to get mine.  I plan to put them in my safe for now since I do not want to damage them and then possibly give them as gifts to those "hard to shop for" coworkers and friends on my shoping list.  How many I give away and to whom will depend greatly on how much they are worth come Christmas   They eventually may end up as a novelty but they may end up worth a whole lot some day - who knows.  Great idea!

[casascius]

Did you send out the first(?) batch?

I can't wait to get mine. They look great!

I hit the post office about 2 hours ago, all orders paid prior to then have been shipped.

[BurtW]

It's really up to you, he's trading a 1:1 value (shipping aside), in my opinion this is a method of cold storage or, as you said, face-to-face trading. (Possibly not face-to-face, if the trades sole purpose was to hide the exchange of a large number of bitcoins, eg. dark net trade.)

If used for transferring bitcoin, it would be awesome if we could send money to the address on the coin. Why is only the first 8 digits on there?

Interesting idea and you just showed me that these are way cooler than I first thought!!  In theory I can make one of these coins worth as much as I want to, right?  I just can't make it worth less.  This proves that these coins are, in fact, one way WALLETS - not just coins.  All I have to do is:

Lookup the entire public key in the block chain.
Send more to that key.
Let's say I send 99 coins to the address.  Wala!  A 100 BTC coin.
I can then give the coin to someone and tell them it is really a 100 BTC coin.
They can verify my claim in the chain.

When they "crack it open" then can transfer all 100 BTC to their account (or wherever).

Also another very useful application is that you can give the coin to someone and then transfer more to it over time AFTER they have it, like give one to a nephew and then transfer more on each birthday - or whatever!

You can meet someone face to face once, give them a coin and from then on you can make payments to them and you know the payments are going to the intended destination, the bitcoin address you gave them!

It looks like these are a very cool way to store (and transfer) any amount of value "off line" - just like the paper wallet idea!

[brendio]

Did you send out the first(?) batch?

I can't wait to get mine. They look great!

I hit the post office about 2 hours ago, all orders paid prior to then have been shipped.

Hi did you get my PM from yesterday?

[inh]

It's really up to you, he's trading a 1:1 value (shipping aside), in my opinion this is a method of cold storage or, as you said, face-to-face trading. (Possibly not face-to-face, if the trades sole purpose was to hide the exchange of a large number of bitcoins, eg. dark net trade.)

If used for transferring bitcoin, it would be awesome if we could send money to the address on the coin. Why is only the first 8 digits on there?

Interesting idea and you just showed me that these are way cooler than I first thought!!  In theory I can make one of these coins worth as much as I want to, right?  I just can't make it worth less.  This proves that these coins are, in fact, one way WALLETS - not just coins.  All I have to do is:

Lookup the entire public key in the block chain.
Send more to that key.
Let's say I send 99 coins to the address.  Wala!  A 100 BTC coin.
I can then give the coin to someone and tell them it is really a 100 BTC coin.
They can verify my claim in the chain.

When they "crack it open" then can transfer all 100 BTC to their account (or wherever).

Also another very useful application is that you can give the coin to someone and then transfer more to it over time AFTER they have it, like give one to a nephew and then transfer more on each birthday - or whatever!

You can meet someone face to face once, give them a coin and from then on you can make payments to them and you know the payments are going to the intended destination, the bitcoin address you gave them!

It looks like these are a very cool way to store (and transfer) any amount of value "off line" - just like the paper wallet idea!

This.

[RSantana]

Nice job on the coins, they are cool. However the trust factor is way to high. I went down this road myself when I created the gold plated CoinBit http://CoinedBits.com.

The original consumer has to trust that Casascius isn't selling them a zero value coin. The circle of trust then gets wider if the original consumer tries to trade the coin. The second person receiving the coin now has no way of verifying the coin originated from Casascius.

Counterfeiting this coin would not be difficult, and would be extremely lucrative if the Casascius coin gained adoption.

This is why I ended up keeping the CoinBit as a novelty or souvenir coin.

[casascius]

Nice job on the coins, they are cool. However the trust factor is way to high. I went down this road myself when I created the gold plated CoinBit http://CoinedBits.com.

The original consumer has to trust that Casascius isn't selling them a zero value coin. The circle of trust then gets wider if the original consumer tries to trade the coin. The second person receiving the coin now has no way of verifying the coin originated from Casascius.

Counterfeiting this coin would not be difficult, and would be extremely lucrative if the Casascius coin gained adoption.

This is why I ended up keeping the CoinBit as a novelty or souvenir coin.

If your CoinedBits had a flat surface about an inch in diameter on them, they could be made to contain bitcoins and people would still happily buy them.

If someone wanted to throw resources at counterfeiting the coin, seeing as people are already willing to pay a 25% premium and shipping on top of that to acquire the coins, why wouldn't they just throw those same resources at legitimate coins and not risk getting their cover blown?  One could just as well counterfeit Bitbills or FRN's.  Further, people are going to be peeling and redeeming a percentage of the coins... until people start complaining in the forums about the existence of counterfeit Casascius bitcoins, for the time being, one can be pretty sure that the Casascius hologram is an accurate indicator of origin.

[RSantana]

Nice job on the coins, they are cool. However the trust factor is way to high. I went down this road myself when I created the gold plated CoinBit http://CoinedBits.com.

The original consumer has to trust that Casascius isn't selling them a zero value coin. The circle of trust then gets wider if the original consumer tries to trade the coin. The second person receiving the coin now has no way of verifying the coin originated from Casascius.

Counterfeiting this coin would not be difficult, and would be extremely lucrative if the Casascius coin gained adoption.

This is why I ended up keeping the CoinBit as a novelty or souvenir coin.

If your CoinedBits had a flat surface about an inch in diameter on them, they could be made to contain bitcoins and people would still happily buy them.

If someone wanted to throw resources at counterfeiting the coin, seeing as people are already willing to pay a 25% premium and shipping on top of that to acquire the coins, why wouldn't they just throw those same resources at legitimate coins and not risk getting their cover blown?  One could just as well counterfeit Bitbills or FRN's.  Further, people are going to be peeling and redeeming a percentage of the coins... until people start complaining in the forums about the existence of counterfeit Casascius bitcoins, for the time being, one can be pretty sure that the Casascius hologram is an accurate indicator of origin.

It would be more profitable to counterfeit the coin than to make a legit coin.

You identified the problem when you said "for the time being". It wouldn't take long for people's trust in the coin to falter.

[julz]

Nice job on the coins, they are cool. However the trust factor is way to high. I went down this road myself when I created the gold plated CoinBit http://CoinedBits.com.

The original consumer has to trust that Casascius isn't selling them a zero value coin. The circle of trust then gets wider if the original consumer tries to trade the coin. The second person receiving the coin now has no way of verifying the coin originated from Casascius.

Counterfeiting this coin would not be difficult, and would be extremely lucrative if the Casascius coin gained adoption.

This is why I ended up keeping the CoinBit as a novelty or souvenir coin.

If your CoinedBits had a flat surface about an inch in diameter on them, they could be made to contain bitcoins and people would still happily buy them.

If someone wanted to throw resources at counterfeiting the coin, seeing as people are already willing to pay a 25% premium and shipping on top of that to acquire the coins, why wouldn't they just throw those same resources at legitimate coins and not risk getting their cover blown?  One could just as well counterfeit Bitbills or FRN's.  Further, people are going to be peeling and redeeming a percentage of the coins... until people start complaining in the forums about the existence of counterfeit Casascius bitcoins, for the time being, one can be pretty sure that the Casascius hologram is an accurate indicator of origin.

It would be more profitable to counterfeit the coin than to make a legit coin.

You identified the problem when you said "for the time being". It wouldn't take long for people's trust in the coin to falter.

Some of this could be reduced with the assistance of a website application which allowed public reporting of coin location by date. (postcode or equivalent)
Phone-apps could be used to quickly scan the public key and check not only that the value exists in the block chain - but to semi-automatically report where the coin is.
e.g push a button that says 'yes - report coin was here now' and the phone uses it's geolocation magic to do it (for some user-determined vagueness of 'here' and 'now')

Some people may have no interest in doing that for privacy reasons - but it could be fun to see where a coin has been.  If you see from the history that the coin was supposedly somewhere that you know it couldn't have been at the time (or already flagged as suspicious due to failed redemption of same code) - you should refuse to accept it - or if too late for that, immediately attempt to redeem the coin on the blockchain and report it if it fails.
Any other people scanning a coin with the same public key would then know also to attempt redemption (or to quickly risk passing it off if they're dishonest!)

Any large scale counterfeiting operation would need to have legitimate public keys still showing value on the blockchain - so if even a few users and especially point-of-sale systems used the casascius website verification app - the profitability and therefore motivation for the counterfeiting would be significantly smaller.

Sound reasonable?
It might be open to some trolling by false reports - but people would have to have come into contact with the coin to learn it's public key to do that I assume.


EDIT:
oh, I just noticed this:

... I'm willing to pgp sign a list of all the Bitcoin addresses used in this project.

That would scupper my idea above.  If it's possible for the public to determine a complete list of coins - then false reporting by counterfeiters/jokesters would be a problem.

[molecular]

cascascius, I can't find where you say this and it's kind of important, but you destroy all existing copies of the privkeys, right?

How do you ensure all copies are destroyed. Are you giving them out to be printed on the back of the hologram or are you doing this yourself?

[molecular]

1 - How does one verify that it was you who made the coin?

1 - I chose a hologram with the name Casascius on it, because that would be prohibitively expensive ($thousands) for someone else to duplicate.  And if they're going to go to the effort, they may as well make their own legitimate coins (clearly there's a demand) rather than perpetrating a fraud that would get quickly found out.

I don't completely agree here. Say this runs for a while and the coins gain a lot of trust and are maybe even used in real life in some community as a local currency commodity of value-exchange.

Some thousands of $ to counterfeit the hologram would then be negligible. Your argument that the counterfeiter could instead just make his own coins is weak, because of all the trust your coins have already gained (no incident of money missing from coin addresses, usage over many months, you being a responsive and respected guy over a long period of time), that cannot be as easily reproduced as the coins themselves.

I think you did a good enough job with the holograms for now, though. It'll do for quite a while.

Thanks for a great job! Any news on international shipping? If I wasn't going on vacation soon I'd offer to be european shipping hub...