Sure, I think there are a million attack vectors for getting these "orbs" to send the same person money multiple times. Crafting a face that doesn't generate a

Sure, I think there are a million attack vectors for getting these "orbs" to send the same person money multiple times. Crafting a face that doesn't generate a hash collision (which would be the goal here) is probably an even easier problem! I'm just pointing out that perceptual hashes do exist.