4 ms·

Does this make sense as a counterexample?: Take a picture of the gold bar, you have now stolen the Bitcoins without taking the bar.

• logicallee 12y ago
  Yes, the counterexample is very good. (If we accept its premises that without the information the bitcoin cannot be stolen - this is not true due to 50% attack and other reasons. Gold cannot physically disappear but bitcoin can logically disappear by network consensus or a new version of the bitcoin network that no longer accepts it and which people adopt for some reason. This was done early in bitcoin's history.) But if we accept the premise, then anyone physically close enough to take a picture (let's wrap the gold bar in a dust cover, so that this entails unwrapping it) can physically steal it. i.e. if you prevent someone from physically stealing it, such as keeping it in a vault, then to a good approximation you've also prevented them from unwrapping its dust cover and reading the engraving. I guess exceptions would be if you have workers who work in your vault but go through metal detectors to make sure they haven't stolen the gold, or the gold is somehow physically too heavy to move in one piece quickly, or somehow you can react to it being stolen and prevent the gold from actually leaving, but not if it remains in the vault. This is getting silly though- it's just as easy to engrave something and then hide it in cast iron that is very hard to get into without tools. I think physical protection from theft is very close to physical protection of a piece of engraving.