Bitcoin Forum

I am looking to do a custom bitcoin hologram. On it will be thermal printed the name of the currency producer's website.

This will work in much the same way as the holograms on the Casascius bitcoins. They will be circular and the same size and have a window to show the first characters of a public address behind the hologram sticker.

This will mean that multiple bitcoin cash producers (both bill and coins) will be using the same custom hologram, with basically a personal identifier for them (their website name). I will act as a single source provider so that a fraudulent printer can't come along and pass off bills as though they came from other cash producer.

This will mean that the rather expensive cost of custom hologram initial runs can be split among a pool of multiple producers, and still maintain the authenticity that a hologram provides. The thermal printing of a domain name on a set of holograms isn't expensive.

I can also provide help with pdf generation software for bill and priv/pub printing.

To be considered, I will need:
* A scanned copy of your passport or drivers license (in case you need to be tracked down for fraud)
* A domain name
* A commented piece of text in a web page the domain name points to to show that you own it
* A few hundred dollars (I'll get a more solid estimate once I see what the interest level is).

So in other words, you won't be able to do this anonymously.

Hmm..  but if one of the participants does compromise the system (inadvertently or otherwise), it stuffs it up for everyone. ie Weakest link...

One thing I recently discovered about sociopaths - is that they don't necessarily care about hiding their identity.  They seem to figure the world owes them stuff, and if they get in trouble with one group of people or in one area, they'll move on.. the world's a big place.

That said - I do think sharing the costs for this sort of thing would be good, just that you might be best off with a maximum of 3 or 4.

edit: or..  for each 3 or 4 participants - release a slightly different hologram design.  Some sort of consortium of physical bitcoin producers could share tips on security procedures etc and even jointly fund projects such as common redeeming websites etc.

Even though I already have my own hologram, count me in, I would like a share of whatever holograms you come up with.

Is this going to be factory thermal printed (sort of the same way I put ONE BTC on my labels)?

I'm interested by the way, I have a potential backer for this here in Australia.

Yep, there will be a coin logo with the domain name of the printer in circular text on the bottom of the coin. It will be factory thermal printed, and I will have no holograms that don't have a domain name printed on them.


Indeed. The holograms will be all the same except for the thermal printing of the domain name. The base hologram will not be branded in any way specifically (just a bitcoin and some frillery to make it hard to clone and look good). I will do some diligence in checking on who is receiving these, but I have to expect that if there are enough producers, there is decent odds that one will scam users. In which case, it is his name on the hologram, and it is his reputation that will be tarnished.

When buying physical bitcoins you are buying trust in an individual.

This will also open up the possibility of two or more producers working together to produce bills where neither party knows the private key of the of the bills.
See: https://bitcointalk.org/index.php?topic=53177
and remove this major problem with physical bitcoins.

The only thing a custom hologram does is strongly verify that the person who applied the hologram is the person identified by the name on the hologram. I am opening this up for multiple parties so that cost of this identifier becomes less of a barrier to entry.

Who's doing them, same guys that did mine?

interested

What a great response. I'll finish up the design and get a quote. This is the same company that Mike uses.

I guess coins can only have two holograms since they only have two sides but bills could have more.  I could see up to four holograms on a bill, one on each corner :)

I'm interested, but like I've said before, I'm just as interested in franchising, or just buying the holo-stickers from someone with an established reputation (Mike, for example). Maybe southerners want to buy tupilakker with bitcoins up their... noses, which would still be valuable after the bitcoin is redeemed (like smashing a piggie-bank without the smashing).

just a random suggestion for bitcoin bills:

You ought to go and get your own specially watermarked paper at yourownwatermark.com.  The "Southworth Collection" paper used on the Ron Paul bills has the distinction of being available at every OfficeMax and Kinko's in the USA, and if you do a lot of these and place a large enough order, the custom watermarked paper will probably actually cost less than what the Southworth paper costs.

Very Interested.
I Had been thinking of doing something similar for sometime.
Too busy with work and family life to make it happen.
I'll be glad to contribute financially.

They don't offer the 100% cotton paper, which will decrease durability. I just sent them an email to see if they can produce that.

I have been happy with the southworth collection, for the fact that they have been able to take a lot of abuse without falling apart the way wood pulp would.

I am going to do some research and talk to the guy that produced the Ithica Hours to see what their production process was. I think a number of improvements can be made, and a watermark is just one of them.

I am considering making also micro-bills that will be be only twice the size of the hologram. This is likely for sub-one-bitcoin amounts.

Very interested!

I have decided I am interested in producing bitcoin cheques over the next few months. They would be single-use, so durability is not too much of a concern. Security of the bicoin cheques would rely on two things:

• The printer can prove that they printed a given document.
• The printer can prove (to themselves at least) that they or their hardware has no way of knowing the private key once the document is complete.

I decided that holograms would just make the cheques more expensive to produce without really enhancing security.

One thing I want to do for printing proofs is generate a bicoin address of the form: 1*pubLic*private*key*. Does anybody want to help with that? The Private key would be public, as implied.

I am trying to understand your concept.  Since you are not going to use any method (hologram, etc.) to hide the private key and you stated you actually want the private key to be visible in the clear, what if I:

1) Go to https://www.bitaddress.org (https://www.bitaddress.org)
2) Print out one public/private key pair from the web site
3) Fund the keypair with the desired amount
4) Hand the paper to someone as payment

That sounds like exactly what you are talking about - or am I missing something?

Printing the public and private keys would look exactly like this (from bitaddress.org):


I do not understand your desire for a different/new format, or what the heck you are talking about to tell the truth.

It isn't possible. 

The only way to get a specific public address is by brute force.  For matching even relatively small patterns it is computationally intensive (search for vanitygen).  Anything beyond a handful of characters becomes computationally infeasible.

You also have the problem of private key being 51 char (in base 58) and the address being only 34. :)

I was planning on the public private key only for "proofs". I want a way to alert people that the test documents are *not* secure.

The actual cheques would use a tamper-evident seal like bit-bills, covered with a silk-screen bearing the name of the printer and possibly series/batch-specific marks.

Edit: I guess I could go for a less ambitious vanity address like: 1*PubLic*.
 

Ahhhhh.  I see. so you are going to hide the private key "inside" but just not use a hologram to do it.  Got it (I think).

You might want to look at using scratch offs. That was what I had as my original concept. The plus is that scratch offs are fun.

Tamper evident generic holograms work well for cheques. They might beat any other method as far as ease of application and price.

Exactly. Don't want to got into more detail until mock-ups are ready. Don't want mock-ups until the vanity address is ready. I am also thinking of using the Eurion constellation (http://en.wikipedia.org/wiki/EURion_constellation) to discourage printing with proprietary drivers or hardware (which can cheat on you).

I would just mark the checks "NOT VALIDATED. FOR TESTING ONLY."

On my laptop:


So if you do not care about case then one every few hours.  I could do a few for you if you want and just publish them here since you do not care about the private keys being made public for these test bills.

I have my own laptop I can leave running for days. Since my timeframe is months, I can generate a much more complex address. The idea of asking for help is I might be able to go for a much longer one, but the exponential rise in difficulty will kill you. DeathAndTaxes' suggestion has merit to. I am considering writing a Postscript file that will do most generation (including ECC math) for me (would likely be run using GhostScript, rather than a fancy printer). The only thing that would change between documents would be the randomly generated 32 byte number the key is derived from.

Currently, my computer situation is a bit of a mess. It is one of the reasons I don't actually have any bitcoins yet.

An yes, the tamper-evident seal was going to be the scratch type. The problem with generic holograms is that a dishonest person can go and buy the same generic holograms to stick on their forgeries. Printing the name of the printer on the hologram is better, but I suspect few people will check such details.

If there's an interest in "community holograms", I would be willing to take up a collection and spearhead an order with the label production company and basically do the following:

1 - Place the order and pay the upfront costs
2 - Communicate to them what exactly we'd be looking for in a label (I would seek 1" round circles, as well as something-like 2"x2" squares, and seek some sort of repeating pattern artwork that works well on both, the only difference being how the sheets are cut)
3 - Post the artwork proposals in the forum and solicit community input before accepting any proofs
4 - Have them ship the entire order to me, and I will forward it on.  I will ask the company to bag each person's order and seal it with their own serial-numbered tamper-evident labels, so basically you'll get a bag sealed with a non-generic hologram I can't replicate.  This way you have physical proof that I didn't keep any of your order.  (They already group and bag them this way anyway, just without the seals, and they surely have a zillion numbered seals laying around because that's a product they sell anyway, they surely can be talked into using a few).
5 - I will also give you a copy of the original invoice so you can verify that the quantity in your bag is the quantity that was ordered.

How it would work if you're interested:

1. You pledge $500 USD, pay equivalent in Bitcoins.  (Easiest way: submit an empty shopping cart on my website that only has "shipping" so you get an address, and write in the Notes that this is for holograms, ignore the shipping amount, simply pay your pledge to the address shown).
2. I can guarantee that either A) I will refund your money, or B) I will send you at least 200 sheets of holograms (each sheet can be either 25 circles, or 9 squares... so if you choose all circles, you'll get 5000 of them).
3. I will require evidence of your real-life identity, and you agree that I will share it if I get a written request to do so.  (Depending on the words you have printed, the hologram company may require some sort of letter or documentation explaining why you/I believe we have the right to print such words on a hologram - a requirement imposed by their trade industry).

The nice thing about this is that most of the expense is in the initial production.  The more people who join the pool, we can choose between either getting more holograms per person (possibly double or triple quantity), or by everybody getting a partial refund.  I would only need a minimum of FIVE paying participants to make this work - and I'd be one of them.

So, if you are interested, I propose you fill out an order on my website and include the following:

1 - your name, address, e-mail, and phone (just fill these into the normal fields)
2 - in the notes, what you want printed on your hologram (note, your text will be lasered and will be rendered as TRANSPARENT on your hologram! - the text will not be part of the 3d-image itself - see how my series 2 coins say "ONE BTC" as an example)
3 - how you would like your order apportioned between circles and squares (in multiples of sheets)
4 - how you would like your order apportioned between silver and gold holograms (they can do both and it's no extra charge)
5 - refund address in case it doesn't work out.
6 - a BTC payment worth $500 USD calculated as MtGox weighted average as of the moment you send the payment, to the address you are given by my website.  (I reserve the right to adjust how to figure the price if it makes a drastic turn one way or another)

I think rather than a hologram, a bill that has to be destroyed to retrieve the private key would be appropriate. Imagine a polymer business-card-sized insert (similar in manufacture to Canada's plastic money (http://news.yahoo.com/blogs/technology-blog/meet-canada-high-tech-plastic-currency-184640433.html)) with the private key, encased in a paper sandwich that forms the "bill". It can be embedded in the paper manufacture like the US security strips are. You have to rip apart the bill to get the key "card" out, and the paper can have overprinting and security features that make detection of the private key through xray/IR very difficult. You do not need to show the corresponding public key on the outside of the bill to look up the face value because it would be from a trusted manufacturer who's product is easily auditable.

Paper can be manufactured without having to send off the job to a coin mint or holo printer. Japan, for example, has a culture of artisan paper makers, and a craftsperson local to you familiar with the art of handmade paper may be interested in a bespoke job to produce custom sheets of paper (think colored paper/threads/etc) with the embedded (waterproof) keys ready for printing the final bill art.

Anti-counterfeit technology may include features such as a hologram, but it need not be employed the same way as the Casascius physical bitcoin.

I have played with the Ron Paul checks I got and did notice that the holograms used on them are not "destructive enough" for a real product.  You need to make sure that removal of the hologram totally destroys the check/bill in a totally obvious way - without in any way destroying the private key.  I think this is one of the things that really needs to be worked out.

I really like the idea of somehow embedding the private key inside the bill so it has to be ripped open to get it out.

Also suggested is to have the stickers from the two sides make contact with each other through some holes in the paper - or something like that...

Thanks for the feedback. For the custom holograms we are going with the company that Mike uses which is much more distractible. I have about 50 more bills in my stock and I think that will end series 2011A for the bills. After that I will be going with the custom hologram and changing up the design a little from what I have learned so far. Series 2012B will have some more difficult to reproduce qualities, be double sided, and be denominated funded bills. I probably will still print a cheque form as well, as people seem to like them.

I like the idea of the holes through the paper to link the double sided together.

That certainly would make it cheaper to alternatives to startup but SHOULD it be cheaper/easier to get into the physical Bitcoin biz?

I mean lets take you for an example.  You "could" rip people off by making copies of private keys and stealing funds however you have already sunk a lot of money into the project.  Couple thousand for custom designed hologram, couple thousand more in runs of the holograms (now on 2nd version), thousands more in physical coins plus the time, energy, and effort put into it.

So while when I buy a coin from you it is possible you "could" rip me off I don't think you will.   If the barrier to entry is lower doesn't that lower the implicit trust in the "issuer"?  In essence they have less skin in the game, less to risk if they decide to run a scam.

Sadly Bitcoin is full of scams, theives, and idiots who will trade their reputation for a quick hundred bucks (or less).  So far the only two significant physical bitcoin operators (you & BitBill) have be legit.  Look at the track record for exchanges, wallets, etc and that in itself is pretty amazing.

There still exists an opportunity for a 2nd issuer to do a 2-part private key.  So you may not necessarily buy his physical bitcoins, but you might buy his Ron Paul (or other) checks if he has a second party contributing a key to his product.

And his physical bitcoins may not be a bad deal after all, since he might charge less. Viewed in the worst light possible, I am already "ripping you off" in a sense, charging you a premium on a coin that is nearly its face value.  If you balance out how much less he might charge versus his risk of scamming you, it's probably still worth buying his coin.

Cheaper to startup means that it will also be cheaper to sell, and push margins way down. So a physical bitcoin might cost a small percentage above actual bitcoin value. This would be a wonderful thing as it would be equivalent to getting cash from an ATM.

Legitimacy is an issue, and questions of how to determine how much a vender can be trusted is difficult. I don't know if the cost to a new custom hologram would deter a scammer. That might just be considered an investment in a large scale scam.

I will be releasing some code on github which will create pdfs easily that output QR codes on double sided slips for behind holograms, and this will make it at least an effort to get the private keys in mass for what you are printing.

In the end, anyone producing physical bitcoins could be a scammer. I trust Mike as much as I could trust someone I have never met, and know only through the internet. That said, he could have been storing the private keys all along and just waiting for the key moment to swipe the many thousands of bitcoins that reside on all those coins.

How do we deal with this situation (outside of not producing physical bitcoins)?

I think the one way would be the multiple private key & public key combined bills which would require multiple producers to collude to steal from users. Since no single operator would be able to have access to the coins, this does a lot to resolve the situation.

If the algorithm can be found for 3 or more operators, I would probably trust it more than most other things.

By lowering this barrier to entry, this will bring more producers to the market, and this will reduce the costs that would be needed for this type of protection. Eventually you will never see single private key physical bitcoins, and double private keys will be the standard.

Lowering the barrier and getting more producers is the first important step in this process.

We could probably make a double sided token that was simply a slug that accepted a hologram on each side.  That could be used to make some neat two-party bitcoins.

The premium would be higher - not so sure it would be worthwhile for 1 BTC at current rates, but 5 BTC and above, would not be so bad.

Just curious, who would be interested in such a thing?

I would be. Bills would also work well too and would be much lighter to ship.

My bitcoin cheque idea resolves some of those problems, but is no magic bullet.

Essentially, the biggest risk mitigation measure is their single-use nature. While a few may end up being used as a "savings wallet", the majority should be redeemed within weeks of being funded. That implies that a would-be cheat never quite knows the optimum time to ruin their reputation for a quick buck. It also makes counterfeiting (economies of scale will hurt small runs) less profitable since it is not known ahead of time how much funding will go to a specific address.

I also plan to leverage existing trust neworks. When printing my bitcoin cheques, the printer will be putting their reputation on the line. They will have a real business outside of bitcoin that they would not associated with bad press. The reputable printers will do everything they can to prove to themselves that they, their employees, or equipment have no way of knowing the private key after printing. This may involve banning cameras during printing, keeping employees with a photographic memory away from the floor during printing, using a hardware random number generator, wiping the local storage on any devices connected to the network during printing (including the press). The point is the printer has only their reputation to prove they are trustworthy. Proving to yourself that you can't know the key simply removes any tempation to tarnish your reputation.

Of course, as I mentioned earlier, the printer has to be able to prove whether or not they printed a given document. This may involve using things like microprinting with access to a high-resolutuion press. My printer does not have that resolution, but it may be able to print that Eurion Constallation even though modern printers may stop printing. I am also considering making each printing its own series with its own silk-screen. The silk-screen would be deliberately damaged (eg: with holes) and stored for analysis if a dispute ever arises. Large print-runs may want to make use of traceable paper as well.