Quote from: yamaka on September 27, 2013, 05:25:52 PM

Hi, we are doing physical coins and we would like to modify printcoins project to add our own design that you can see here: https://bitcointalk.org/index.php?topic=292223.msg3127709#msg3127709

Would be it possible and how we can do it ?

What's the appeal?

If anyone tries to spend a paper bitcoin bill, the first the acceptee would need to do is verify that there are in fact coins associated with the bill, followed by moving the coins represented by the bill to a new bitcoin address in case the bearer kept a copy of the private key themselves. Even if you knew for 100% certain that they didn't keep the key, you'd also need assurance that the bearer didn't print two bills rather than one, or even that a Piece of malware wasn't on their computer that surreptitiously transmitted the pdf or just the private key in the print file to someone else.

When I saw this topic and started reading, I thought it was so old that these concerns would have shelved the idea; can you explain how your project would attempt to address that, or if even Addressing those concerns is even possible?