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Author Topic: CASASCIUS PHYSICAL BITCOIN - In Stock Now! (pic)  (Read 118818 times)
molecular
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October 26, 2011, 02:23:04 PM
 #201

Yes, but I'm talking about an organized criminal with the same tooling available to himself as Casascius passing off spent coins as unspent by putting a new hologram sticker on them.  Don't get me wrong, I'm not trying to belittle his acheivement.  I'm just concerned that there will eventually be a determined criminal element that will undermine the trust in bitcoin in general if they can create distrust in physical bitcoins.  It's not like doing so would actually be illegal in most places, since bitcoin isn't an official currency anywhere.

Yes, I think, unfortunately, this could be done. The hard part is probably getting the hologram manufactured.

Mike (or anyone), can you elaborate on how hard this would be or if there'd be any other hassles for a counterfeiter?

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October 26, 2011, 07:52:33 PM
 #202

These are lovely, but how do we know that the manufacturer doesn't keep a copy of the keys and will spend them if they get very valuable?

I asked myself that same question and mailed Casascius about it but unfortunately got no reply so far.

Even though I do trust Casascius as he obviously is a long time member of the BTC-community and doing a hell of a lot to help Bitcoin develop I would like to know how he handles the private keys stored on the coins and if and how he destroys them after charging the coins and how he makes sure noone else can ever recover them (by finding an old harddisc or stealing a laptop or whatever).

Casascius: could you make a statement about this matter? I also believe that transparency in this regard would make far more people trust in the physical coins and improve your turnover. To be honest, that missing answer is all that is holding me back from buying coins off you Wink.

Btw: have you noticed that there is a typo on the coins? The smaller, repeated lettering on the hologram is missing the second 's' and says 'casacius':

https://www.casascius.com/btcpile2-1200.jpg

Best regards and thanks for your efforts and your reply!

joe





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October 26, 2011, 08:50:16 PM
 #203

Yeah, in short, I produced the private keys offline, printed them once, wiped the drive.  Wiped with cp /dev/zero /dev/sda twice.

The only copy I have is the physical copy that will go inside future coins.  I don't have a copy of any I have sent out already.  I don't need the private keys to load them, just the bitcoin address.

Yes I am aware of the typo on the holograms.  Didn't see it until it was too late.  Another batch of holograms is in production with this fixed (and other improvements).

Companies claiming they got hacked and lost your coins sounds like fraud so perfect it could be called fashionable.  I never believe them.  If I ever experience the misfortune of a real intrusion, I declare I have been honest about the way I have managed the keys in Casascius Coins.  I maintain no ability to recover or reproduce the keys, not even under limitless duress or total intrusion.  Remember that trusting strangers with your coins without any recourse is, as a matter of principle, not a best practice.  Don't keep coins online. Use paper wallets instead.
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October 26, 2011, 09:08:42 PM
 #204

Yeah, in short, I produced the private keys offline, printed them once, wiped the drive.  Wiped with cp /dev/zero /dev/sda twice.

The only copy I have is the physical copy that will go inside future coins.  I don't have a copy of any I have sent out already.  I don't need the private keys to load them, just the bitcoin address.

Yes I am aware of the typo on the holograms.  Didn't see it until it was too late.  Another batch of holograms is in production with this fixed (and other improvements).

Waaaat? You mean all coins purchased before now are the "rare 2011 casascius with typo" and sell for a much higher price at some point in the future? Nice! Wink How many (will) have the typo?

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October 26, 2011, 09:27:47 PM
 #205

Yeah, in short, I produced the private keys offline, printed them once, wiped the drive.  Wiped with cp /dev/zero /dev/sda twice.

The only copy I have is the physical copy that will go inside future coins.  I don't have a copy of any I have sent out already.  I don't need the private keys to load them, just the bitcoin address.

Yes I am aware of the typo on the holograms.  Didn't see it until it was too late.  Another batch of holograms is in production with this fixed (and other improvements).

Waaaat? You mean all coins purchased before now are the "rare 2011 casascius with typo" and sell for a much higher price at some point in the future? Nice! Wink How many (will) have the typo?

Wish I had bought more of them and not any given away.

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October 26, 2011, 09:33:29 PM
 #206

THe ones I'm selling now still have the typo

I've sold about 2000 so far

New holograms are a week or two out

Companies claiming they got hacked and lost your coins sounds like fraud so perfect it could be called fashionable.  I never believe them.  If I ever experience the misfortune of a real intrusion, I declare I have been honest about the way I have managed the keys in Casascius Coins.  I maintain no ability to recover or reproduce the keys, not even under limitless duress or total intrusion.  Remember that trusting strangers with your coins without any recourse is, as a matter of principle, not a best practice.  Don't keep coins online. Use paper wallets instead.
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October 27, 2011, 08:25:46 AM
 #207

Yeah, in short, I produced the private keys offline, printed them once, wiped the drive.  Wiped with cp /dev/zero /dev/sda twice.

I heard some time ago that FBI/CIA stated that they can read data from hard drives that has been zero-filled once or twice.

Perhaps you should do it few more times, with random data every time instead of just zeros.

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October 27, 2011, 09:07:28 AM
 #208

I read several times, that even a single pass of overwriting cannot be restored.

german source: http://www.heise.de/ct/artikel/Datenpuzzle-763739.html

according to heise its a myth that the agencies can restore data on magnetic medium that easy.
it was not possible to restore these data with professional tools nor direct access an the hardware.

I would be interested if any of you can proof the opposite.

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October 27, 2011, 10:51:23 AM
 #209

Yeah, in short, I produced the private keys offline, printed them once, wiped the drive.  Wiped with cp /dev/zero /dev/sda twice.

The only copy I have is the physical copy that will go inside future coins.  I don't have a copy of any I have sent out already.  I don't need the private keys to load them, just the bitcoin address.

Yes I am aware of the typo on the holograms.  Didn't see it until it was too late.  Another batch of holograms is in production with this fixed (and other improvements).

Waaaat? You mean all coins purchased before now are the "rare 2011 casascius with typo" and sell for a much higher price at some point in the future? Nice! Wink How many (will) have the typo?

Wish I had bought more of them and not any given away.

Hehe. I'll keep giving them away, they make such a nice gift and talk-starter. It's amazing how people seem to "think with their hands", playing with (and looking at) the coin when you explain hashing functions and distributed book-keeping. Touch activates brain Wink


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October 27, 2011, 10:52:57 AM
 #210

Yeah, in short, I produced the private keys offline, printed them once, wiped the drive.  Wiped with cp /dev/zero /dev/sda twice.

The only copy I have is the physical copy that will go inside future coins.  I don't have a copy of any I have sent out already.  I don't need the private keys to load them, just the bitcoin address.

Yes I am aware of the typo on the holograms.  Didn't see it until it was too late.  Another batch of holograms is in production with this fixed (and other improvements).

Thanks for quick reply and clearifying that. As mentioned I would state that on your website as well if I was you.

I'll order some, _despite_ the typo Wink.

Joe




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October 27, 2011, 10:56:37 AM
 #211

Yeah, in short, I produced the private keys offline, printed them once, wiped the drive.  Wiped with cp /dev/zero /dev/sda twice.

I heard some time ago that FBI/CIA stated that they can read data from hard drives that has been zero-filled once or twice.

Perhaps you should do it few more times, with random data every time instead of just zeros.

In this case I wouldn't be worried because of FBI / CIA / NSA or alike.

Governments have much more efficient ways of getting hold of our money, they wouldn't bother stealing bitcoins  Grin.

joe

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October 27, 2011, 01:54:40 PM
 #212

Yeah, in short, I produced the private keys offline, printed them once, wiped the drive.  Wiped with cp /dev/zero /dev/sda twice.

I heard some time ago that FBI/CIA stated that they can read data from hard drives that has been zero-filled once or twice.

Perhaps you should do it few more times, with random data every time instead of just zeros.
This is an exciting day for me!  Finally, a post that I can claim to know something about and answer!  I started designing firmware for hard disk drives in 1987 (a 20MB 3.5" half high) and I am currently working on the next generation SMR drive (>5TB) so I now have almost 25 years experience in the industry.

This myth may have actually been true in the distant past when the data tracks were far apart, there was still a guard band between the tracks, and the data was recorded on the drive in a linear fashion (LMR).  On antique drives (>15years) it may have been possible with extremely expensive equipment to read some of the data left over in the guard band between the tracks after a single write pass.

However on modern drives the magnetic domains are recorded perpendicularly into the media (PMR), there is no guard band, and the tracks are so close together that you are lucky if we can read back your original data at all Smiley  In fact on modern drives the data is so densely packed and noisy that almost every single sector read back requires massive error correction in order to recover the original data.  BTW this noise/error situation on solid state flash drives is even worse.  These devices require even more error detection and correction than rotating magnetic media.

Now, on the next generation SMR (Shingled Magnetic Recording) drives the tracks are now overlapped. So, a single write pass will cause the entire drive to be re-shingled and this will overwrite every magnetic domain on the drive.

The real issue is that a single write pass of a 3TB or greater drive takes forever and a day.  So I would suggest that if you need to wipe the drive on a regular basis you get a secure TCG Opal or TCG Enterprise drive.  That way all you have to do is change the key and instantaneously all the data on the drive is gone since the old key is now lost forever making the AES encrypted data on the drive unrecoverable.

One final note regarding:
Quote
Perhaps you should do it few more times, with random data every time instead of just zeros.
All modern high speed serialized data transmission and storage channels (SAS, SATA, PCIe, hard disk drives, etc.) must randomize the data in the channel in order to minimize RFI/EMI issues.  In other words all the data is randomized so it does not matter what data you write to the drive (all zeros, all ones, 0x55, etc.) it will all end up being combined with a pseudo random number stream before it is recorded/transmitted anyway.

Our family was terrorized by Homeland Security.  Read all about it here:  http://www.jmwagner.com/ and http://www.burtw.com/  Any donations to help us recover from the $300,000 in legal fees and forced donations to the Federal Asset Forfeiture slush fund are greatly appreciated!
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October 27, 2011, 02:51:24 PM
 #213

I would think that the higher risk if somebody broke into Casascius's home is the physical bitcoins and paper wallets he stores there, which if he's done things as he's told us he has (and I have no reason to believe that he hasn't), shouldn't really offer risk to those coins already in the wild. The main problem I could foresee is if there is a period of time that he stores coins before loading value onto them, and those coins were stolen, then it would make it even more needed that people verify the balance of coins before accepting them.

On another note, especially if there's going to be more than one valid-looking hologram, I think it would be wise for Casascius to put on his site guidelines for "How to determine a Casascius coin is genuine", including detailed pictures of authentic and "used" coins.
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October 31, 2011, 10:40:28 PM
 #214

As great a conversation starter that the coins are,  I suspect their biggest short term benefit will be that people can now buy
Bitcoins with a Credit card or Paypal.

Now just about anyone has a convenient way to buy Bitcoins.
The premium on the 25BTC coins is very reasonable, and will be even better on the 100 BTC product that is coming soon.

I'm suspecting that this may become a way to allow exchanges, or others, to sell Bitcoins safely using Paypal and Credit cards.

Any thoughts?

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November 01, 2011, 04:53:57 AM
 #215


I'm suspecting that this may become a way to allow exchanges, or others, to sell Bitcoins safely using Paypal and Credit cards.

Any thoughts?

Roger, thanks for sticking your neck out. I hope you know what you're getting into.  Selling physical bitcoins may not be nearly as risky as selling digital ones but I'd still be cautious.  How's your fraud prevention? You're accepting a reversible payment method and paying out an irreversible one, so you're taking quite a risk.  From my experience observing the e-gold community, when someone tried accepting plastic for an irrevocable currency, they were eventually hit by a huge number of purchases using stolen credit cards, well as man in the middle scams and auction scams.  Only the companies with the best precautions survived.
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November 01, 2011, 12:09:51 PM
 #216

As great a conversation starter that the coins are,  I suspect their biggest short term benefit will be that people can now buy
Bitcoins with a Credit card or Paypal.

Now just about anyone has a convenient way to buy Bitcoins.
The premium on the 25BTC coins is very reasonable, and will be even better on the 100 BTC product that is coming soon.

I'm suspecting that this may become a way to allow exchanges, or others, to sell Bitcoins safely using Paypal and Credit cards.

Any thoughts?

While I trust Mike Caldwell a lot, there is still a possibility that he's keeping the private keys (I'm not suspecting he does, but it's a possibility). So there's still a trust issue involved. I wouldn't confidently use the 100 BTC coins for storage of my wealth.

I don't quite understand why you say it'd be somehow safer to deal in physical bitcoins than in virtual ones. The problem with paypal does not lie in the delivery of the bitcoins, but mainly in the reversibility of paypal transactions and the fact that paypal does not guarantee to keep your account usable. Did I misunderstand something?

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November 01, 2011, 12:19:13 PM
 #217

Quote
Are physical Bitcoins legal?
No, it's a crime punished with death penalty and you will also go to hell.

And Santa Claus will cry.
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November 01, 2011, 01:25:36 PM
 #218



While I trust Mike Caldwell a lot, there is still a possibility that he's keeping the private keys (I'm not suspecting he does, but it's a possibility). So there's still a trust issue involved. I wouldn't confidently use the 100 BTC coins for storage of my wealth.

I don't quite understand why you say it'd be somehow safer to deal in physical bitcoins than in virtual ones. The problem with paypal does not lie in the delivery of the bitcoins, but mainly in the reversibility of paypal transactions and the fact that paypal does not guarantee to keep your account usable. Did I misunderstand something?

The increased perceived risk at 100 BTC is understandable and was anticipated. So this bar comes in 2 versions, a 100 BTC one, and a blank one where you roll your own private key and denominate it yourself.

Normally people aren't going to be transacting the bars face to face so it is less of a concern whether it has a casascius hologram. The main attraction of the bar is how it looks and as a savings wallet.  In my view, if you CAN produce your own private key, you should. There are tons of designs of generic holograms on eBay (diameter 1 inch or 25.4mm, I thought I saw a gold "fireworks" one the other day) or you could just use a regular foil sticker.

As for physical goods, credit cards and PayPal tend to give leverage to sellers who can prove they shipped physical goods to the buyer's confirmed address especially if the buyer had to sign for them.

Companies claiming they got hacked and lost your coins sounds like fraud so perfect it could be called fashionable.  I never believe them.  If I ever experience the misfortune of a real intrusion, I declare I have been honest about the way I have managed the keys in Casascius Coins.  I maintain no ability to recover or reproduce the keys, not even under limitless duress or total intrusion.  Remember that trusting strangers with your coins without any recourse is, as a matter of principle, not a best practice.  Don't keep coins online. Use paper wallets instead.
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November 01, 2011, 01:45:29 PM
 #219



While I trust Mike Caldwell a lot, there is still a possibility that he's keeping the private keys (I'm not suspecting he does, but it's a possibility). So there's still a trust issue involved. I wouldn't confidently use the 100 BTC coins for storage of my wealth.

I don't quite understand why you say it'd be somehow safer to deal in physical bitcoins than in virtual ones. The problem with paypal does not lie in the delivery of the bitcoins, but mainly in the reversibility of paypal transactions and the fact that paypal does not guarantee to keep your account usable. Did I misunderstand something?

The increased perceived risk at 100 BTC is understandable and was anticipated. So this bar comes in 2 versions, a 100 BTC one, and a blank one where you roll your own private key and denominate it yourself.

Normally people aren't going to be transacting the bars face to face so it is less of a concern whether it has a casascius hologram. The main attraction of the bar is how it looks and as a savings wallet.  In my view, if you CAN produce your own private key, you should. There are tons of designs of generic holograms on eBay (diameter 1 inch or 25.4mm, I thought I saw a gold "fireworks" one the other day) or you could just use a regular foil sticker.

As for physical goods, credit cards and PayPal tend to give leverage to sellers who can prove they shipped physical goods to the buyer's confirmed address especially if the buyer had to sign for them.

I see (about the 2 bar versions). This is of course something quite different. You wouldn't use that to make physical payments, which I could well imagine being done with the 1 BTC coins. I see the use as a cool "key storage for savings wallet", though.

Thanks for clearing things up for me about paypal/physical shipping, makes sense.

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November 02, 2011, 11:16:51 AM
 #220

I see that Memory Dealers is selling the 100btc bars now. Do they have the full-length private key affixed, or do they also use a mini version?

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