Topic: Print your own bitcoin bills - print.printcoins.com - page 2. (Read 23375 times)

When I locally install the source on a webserver

Well, I cant figure out why the denomination options arent showing up. Seems its pulling them from the php script. I dont know php well enough =( .. help?

Everything else works tho..

Was able to fix a syntax error in form.html .. the values now properly show up =)

That's what tamper-proof hologram stickers placed over the private key QR is intended to solve, similarly to the ones used on Cass coins covering the key. It seems to me you would have to use sufficiently thick paper as well.

I really think these can be a good idea and useful if they were produced by a reputable company at specific denominations.  After dealing with hurricane Sandy and not having power for a week, digital currency doesn't help if you can't get to it.  If a large company like MT Gox distributed them then I could see them taking off as far as trading goes, because you know what your getting. . . then again the other problem is making sure that the digital money wasn't used already which presents another problem . . . ugh.

multiple ways:
http://printcoins.com/redeem

So it gives the private key. Is there a web service for uploading the private key to use the BTC?

I am thinking about giving out some of these for Christmas.

@robkhor
You can get a free certificate that is acceptable by almost all browsers at StartSSL.com. These are well known and used by many sites successfully. I've used them in the past without issues.

Is it something like a legal tender? 

Business idea for you: With a desktop version or even a JS version you could rather sell cool bitcoin hologram stickers and paper with some suitable background artwork. The notes should also have space possible to customize besides the codes and amounts, for use as gifts.

With that and one extra QR code to be used to identify the issuer (by PGP signature of email address?), you will have set up anyone to start issuing their own bitcoin banknotes!

+1 for post #40 from canton for this good summary.

...and +1000 for robkohr's proof-of-concept printcoin web page and for providing the source code.

Of course having an EASY Java Script solution like bitaddress.org would be the nicest solution for the people who cannot easily set up a local web server but still want a save solution to print their own printcoins. --> Maybe I have an idea here...
--> ...concerning bitaddress.org (which is fully javascript based), I am able to generate proper PDFs extremely easily! I just use the "Print" button and print to my PDF-printer!!! (this is extremely easy under Linux (=my case), but free PDF printer drivers also exist for Windows and can be downloaded and installed at a click of a button).

So, robkohr (or any other programmer here), could you imagine considering offering a JS-based printcoin.com implementation?

I would use the JS-based bicoinaddress.org straight away, but it lacks two features for me (both of which printcoins.com offers):
- entering my OWN private keys (instead of having new random ones generated for the printed bills)
- the secret key QR code size is too large (unlike printcoin bills) to be covered by a 2.5 cm (1 inch) hologram.

Update: I have just requested here enhancement of the javascript code on bitaddress.org - maybe this is the more reasonable approach, since the codebase in javascript (a single html file) is already available.

@robkohr - hey just a quick note to say I think this is a pretty darn great start, and it's very kind of you to make this an open source and apparently noncommercial project. I also appreciate that your webpage has end-to-end instructions, including where to buy security holograms which is a nice touch.

For those crying spam/fraud/etc. the only fault of robkohr is that he didn't specify up front that this code has the potential for air-tight security by being run on local servers, and/or converted to javascript and run over SSL, etc. On the other hand, anyone crying 'scam!' should be smart enough to know that the current online version is a proof of concept, a starting point us to try out some small conversions -- clearly not a clearinghouse where anyone should dump hordes of coin. I believe robkohr's intentions are pure, but it would be silly to trust large amounts of coin with an unencrypted website on a webhost which may or may not be compromised by hackers. (Dollars to donuts, I'll bet hackers are trying to compromise printcoins.com right now since it's probably easy pickings.)

Here's what I love about printcoins:

* converts bitcoins to a tangible exchange, which makes it possible to engage ordinary citizens in bitcoins not just übernerds. For example, some workers are in my backyard right now are building me a chicken coop. They don't know squat about bitcoin. But I could probably pay them in bitcoin if I had a nice looking bill in my hand and explained to the foreman, "hey, if you're a gambling man, I'll pay you 25% in this very weird currency which has increased in value a few hundred percent in just a few months. Just hold onto this bill and don't lose it, and here's how you use your cell phone to see what it's worth from time to time."

* (once run on a local server) doesn't require trusting anyone with your wallets/addresses. I've loved the idea of buying Casascius coins, but I just can't get over my paranoia stemming from the fact that criminals have a huge motivation to insert themselves into the minting process. I don't just mean hackers, I mean people physically breaking into the minting premises and causing mischief.

What printcoins represents is a huge step towards easy distributed "minting" which is really the key to using bitcoin without putting your bitcoins online where hackers are trying -- and succeeding -- to steal them.

I like this service! How about a really minimalistic design too? Like the one bitaddress.org has. Could be useful if you want to take a paper backup of thousands of addresses.

I just had an awesome laugh at the troll moronic newbies yelling and screaming that data is being stored on the server.

Why is it open source?

You call us the fools yet you could easily run a local webserver, closed from internet acccess and still - no data will be recorded.

Amazing to see the amount of intelligence patiently combating the idiots. Well done

Btw, Im going to put this into use here in NZ. Many people will be interested, especially seeing it on paper...

I tried print.printcoins.com and it worked for each of the designs until I tried turing. Then it only displayed a half-finished loading icon. Now no matter what I do, that's all I get.

Thanks rate5, all fixed.

Just tried this on your site, unfortunately I got this error:

I just added Psy's design. Take a look at it here:

http://tinyurl.com/bitbill

Note: By the way, do not use this set of bills generated by this url. They are using private keys that will be available to all. Go to http://print.printcoins.com to generate your own.

if it only needs to be run on a bare server with php, then a lot of the editors include a preview mode that should work, get a php editor that has a preview (i use 'php expert editor' first and only one i've tried) install php(might have to set the path to php in the editor options), open script, audit script, run script, done

Wow, didn't think this would go down the scammer territory path. For those who wish to view the source code, but want to get right to the meat of where the action is:

https://github.com/RobKohr/print.printcoins.com/blob/master/index.php

This is where I wrote all of the code, everything else is just library stuff. Nothing writes to a file. Nothing writes to a db. It takes in input, and spits back a pdf. Yep, it is http, rather than https. If anyone wants to buy me a cert for this one off project, I'll take it Otherwise you will have to consider a possible man in the middle attack.

The reason this is server side rather than js is that I have not found one decent pdf creation library written in javascript (just a couple half hearted attempts that were useless). pdf's are the simplest way to create something that will print to exact dimensions on the web.

If you have no faith in me, then download it and run it yourself, that is what the code is for. The website is just up there so you can be lazy if you trust me. I would be more worried if someone created an executable to do this on your home machine, as that would be able to get to your actual wallet. Or just don't use it at all. 

As far as the actual usefulness of bitcoin bills, well that is a good question. It could be handy for off the grid transactions where both parties trust each other. I find that most people use them as gifts or as a way to sell bitcoins to others as an investment, but where the other person just doesn't want to bother with setting up the tech to handle bitcoins. For real commerce in physical form off the grid with untrusted parties, significant steps would need to be taken to prevent counterfeiting as well as private key extraction. Right now, I think only Casascius has a product that I would accept as money from a stranger on the street. It would be difficult and expensive to forge that product. When bitcoin is common enough to easily find merchants in meatspace to do transactions with, I think there will be plenty of physical forms out there. Cash is a much more natural for exchange than two people tapping on their cell phones and then waiting for the transaction to be verified. It is also much more satisfying to be paid in cash, and more untraceable (for both bitcoins and fiat).

So far, I have loading the SVG into an iframe and updating the address/key in JS.
I will load the SVG externally because 4MB of data per artwork is too much to embed or download on initial load. Also, this makes it easier to incorporate other designs.
I will put some thought into signing the final SVG because it can include JS.

Next step for me is getting a QR code into SVG format... or use CSS positioning.