Topic: CASASCIUS PHYSICAL BITCOIN - In Stock Now! (pic) - page 47. (Read 130354 times)

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.

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?

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.

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  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:
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.

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  .

joe

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 .

Joe

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

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.

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.

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

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

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! How many (will) have the typo?

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).

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 .

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

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?

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.

Journalists stumbles upon casascius. Feels need to write some shit-piece about it. News at 11.

Another FUD hit-piece. They are so dumb if they think stories like this will kill bitcoin. Don't they know that even bad publicity is good for bitcoin? Maybe their plan is to keep it low while they are buying slowly and steadily while keeping speculators at bay.

He'd have some other, much more evil options.

I obviously need a new camera, but the difference should be apparent.