3 ms·
You divide the cards stack in two and put the top part at the bottom of the other part (which was the bottom part and will be now the top). The relative order o
by Emigre_ 4y ago
You divide the cards stack in two and put the top part at the bottom of the other part (which was the bottom part and will be now the top). The relative order of the cards is maintained: you don’t shuffle them. But if you cut them in this way several times, it obfuscates the original location of the cards (as it’s in practice impossible to follow their position changes) so you can’t tell who put which card where. Therefore the final arrangement, when revealed, is anonymized.
- maxbond 4y agoOkay gotcha, what was confusing me was how we could randomize it and preserve the relationships of the cards at the same time, but I see now this shuffle is more like "secure by magic trick" than "secure by cryptography", that makes sense. Or equivalently, we put it into a black box, that flips a secure coin, and either does or doesn't swap the cards. Thank you.