Depending on how broadly you want to define "hash a physical object", there is a trick that was described by this memorable HN comment: https://news.ycombinato

Depending on how broadly you want to define "hash a physical object", there is a trick that was described by this memorable HN comment: https://news.ycombinator.com/item?id=18138699 https://news.ycombinator.com/item?id=18138699