Topic: (pics) Physical Bitcoin Bills - For Real World Transactions - Printcoins.com - page 4. (Read 8824 times)

Since you must send btc to each public address, you can determine the firstbits (I see you've got one in your sig!). Random 1+7 characters is more than 99.9% likely to be unambiguous today (no, I did not calculate birthday paradox *). You could post-scan all of the addresses and pull any ambiguous prefixes. Anyway, with a large enough production, I think a transparent list is as good as anonymous. Once someone sees the physical address, how does the public list compromise identity? - or vise versa?

*
days|keyspace d =58^7
people|address n ~= 8 - 800 Million
d! / dn(d-n)!

I published all my Casascius Coin addresses, but partly out of need:  I'm only putting 8 characters on my coins, and without the list, one cannot be certain of the full address.

Publishing a signed list also has one useful effect, it would also enable someone to prove to a court I had scammed, if I were to ever scam.  Me scamming, for example, would result in a lot of people holding intact coins but with balances spent off them... would be strong evidence against me, and therefore a strong scam deterrent.

I do not think publicly listing the addresses serves your customers.  A customer of yours can list the addresses of their bills themselves if they (why??) wanted to. 

No, anonymity doesn't truly exist here. The difference is that it makes them "easily" accessible to everyone rather than the few that would know.

True Transparency is always a good thing, although it might have negative or positive results.

Thank you all for all your feedback!

A couple updates:
 
  * Minimum order requirements have been removed
  * International orders have been added. If you would like to help translate the bill into your local language, I can do that with that for no extra charge.

I also changed the address part of the form to a text area block. This should accommodate for some of the more interesting addresses in other countries.



I was wondering, why would making the list of public addresses be a good thing? Doesn't that destroy the anonymity factor?

I was thinking a better way would just be a verification page. Enter in a public address and complete a captcha, and it verifies whether this was a bill that was shipped.

It's all in the budget.  Certainly would enhance collectibility if he could pull it off.

Google brings me to yourownwatermark.com.

Would be nice, but probably not critical to have a very nice custom watermark on the paper...

He seems to already be using a pretty decent quality of paper.  "Security paper" could mean anything - a unique label is what will really make the biggest difference.

Ordered one of each for fun.  I ignored your minimum 10 BTC order limit and sent you 3.04 BTC.  If you are really going to stick to your minimum 10 BTC limit then send my BTC back to me at http://firstbits.com/1burtw and cancel the order.

Please listen to Mike, he really knows what he is talking about.

I would say, great proof of concept.  Here would be my advice.

First of all, custom holograms are a must.  It just doesn't make sense to use a generic hologram that's on eBay.  PM me and I'll tell you who did mine.

Be aware, a new order of holograms will set you back about $2k - $2.5k and you'll need about 6 weeks lead time.  So if you're gonna do it, start now.  On the flip side, these guys can produce holograms in practically any size.  For reference, mine are a 1" circle.  They can cut them however you want though, they come in sheets.  Since these are going to a piece of paper and size isn't a factor, if I were doing a project like this, I would totally be doing a huge eye-catching square sticker (at LEAST 2"x2"), which would be plenty of room to make a gorgeous holographic masterpiece (and these guys will help you).  You do this right, and this alone will sell bills.  Put a big fat-ass B logo hologram on there, and I'll want a fistful of them.

Next, it shouldn't be too hard to generate your keys on an offline computer.  You say you're firewalled...what do you need an internet connection for?  And you say these never touch the hard drive -- you're sure, not even via the page file, or via the print queue?  Sterility is easily achieved so no excuse to not do it.  If you're going to do this for real, you really need to format a fresh hard drive, generate your junk with no internet connection whatsoever, print your shiz, and then zero the drive.

The Courier and Arial (or whatever other built-in) fonts have got to go.  Consider the Ubuntu font.  Google for it.  I would also like to suggest scrapping the "bitcoin not legal tender" bit.

The load-it-yourself non-denominated bill should be more like a "bitcoin cheque" and be formatted to look like a cheque, not cash, in my opinion.  The user should be led to write out the amount in script as well as numerals: "------TEN------ bitcoins.... 10.00 BTC".  (Notably, your bills already look like cheques, they just lack the formatting of one.)

Finally... I would really rethink having "load-it-yourself" bills that are loaded by the customer.  YOU SHOULD LOAD THESE.  The whole point of having a bill is for the recipient to NOT have to scan it.  Fortunately you have thrown a generic hologram on there so you haven't really done any harm.  But if and when you start throwing holograms on there with your name, you want to do your best to make sure that all bills in the wild are actually loaded.  I would also have the hologram guys laser-etch the denomination into the edge of the actual holograms (like you may notice on my 2nd series).

Thanks!

Yep:


The center of the sticker has a paper square under it to protect the QR code, so it doesn't come apart in the middle. The edges fall apart pretty easily when you try to remove it. It also totally loses its stickiness.

Can you show us what it looks like after the sticker is taken off?

They will be public as they are shipped (they are scanned on the way out the door).

No, 20 of 50 (I have a 100 pack, double sided holograms). If I sell out, I will be doing a custom one for version B (and then these will be collector items

They are too generic though, you are correct. I have a design already, and if I sell out of my first batch I will be doing a custom hologram.

It is cool, and I respect that.

My real name is Rob Kohr, and my personal website is robkohr.com, and from there you can probably find a lot of info about me (probably more than Mike). I use RobKohr as my username everywhere (I am not much on being anonymous).

The private (and the public keys) never actually touch a hard drive. I generate them during the printing process for the bills, and they exist in an in-memory pdf file format going to my printer (the pdf file is not saved either). I use a Mac, which while not bulletproof, viruses are rather rare for. I also am a programmer at Intel, and know a little bit about security. My machine is behind a firewall.

I will be publishing the public keys (unless requested by the buyer) when they are shipped. The pre-shipping process is to scan the public keys with my phone and drop them in an email to the recipient of the bills.

Do you have a list of Addresses that are available to the public?

Also, I would consider going through a company to create a unique tamper evident hologram. I sincerely hope that you did not sticker 1000 of your bills already.  

Sure I can.  I (me Burt) trust Mike.  I can do that if I want to.  Not 100% sure why I do but some factors are that he uses SSL, he funds the coins, he has been around a long time, I have PMed him and gotten to know him, he makes more money selling coins than he would ripping people off at the current level of coin production.

I do not know this guy... yet.

If these things were in general circulation and there were a lot of them he could make a lot of money in one giant scam - that is obvious.

That also applies to the coins, true.