my poor understanding of it is that it's like a split tally stick. https://en.wikipedia.org/wiki/Tally_stick#Split_tally https://en.wikipedia.org/wiki/Tally_st

my poor understanding of it is that it's like a split tally stick. https://en.wikipedia.org/wiki/Tally_stick#Split_tally https://en.wikipedia.org/wiki/Tally_stick#Split_tally So what if you put each half of split tally stick in a box hidden from view then move them a light year apart and then open your box? You immediately know what's on other stick but you can't change it anyway. and also the act of viewing the stick destroys it.