Re: [SERVICE] Roll your own Casascius Proof-of-Age Certificate
...Couldn't someone just look up the public address to see when the coin was first loaded?
I'm not sure why a separate proof-of-age would be needed.
I'm not sure why a separate proof-of-age would be needed.
That doesn't work because a counterfeit could have the same address printed on it as the original.
And relying on a downloaded zip file to conduct the proof in the future sounds risky. Why not just have the hash be of some text printed on the card, naming the type of coin and its address? Then the card could be locked in a safe, and in 10 years when USB drives and all optical media is extinct people can still type it in to do the check 
Again, someone could make "a copy of the coin", a counterfeit. You proof would be valid for that counterfeit also.
The idea with the image is that you can't counterfeit all the little scratches and imperfections that makes every coin an individual of sorts.