I'm confused, is the private key represented on the face of the note? If so, isn't there a risk that anyone who ever sees the note might spend the bitcoins, breaking the association with the note?
Great design.<p>Putting high achievers face on currency will quickly become a political issue. There are many cultures of people with almost no scientific achievement. Their people would never be on that currency.<p>Bitcoin paper currency will need more thought. Someone could steal your currency just by looking at it and thats not secure. We probably could take a range of coins and designate them as paper only currency and digitizing them would not be allowed.