3 ms·
I just go with "some things are easy to do but hard to undo - like breaking a glass of water. Easy to do, hard to undo." At least as a first explanation of what
by edanm 14y ago
I just go with "some things are easy to do but hard to undo - like breaking a glass of water. Easy to do, hard to undo." At least as a first explanation of what we're trying to achieve in the first place.
Also, I love the "Waldo" example of zero-knowledge proofs: I want to prove to someone that I found Waldo in a "Where's Waldo" puzzle. How do I do this without showing them where Waldo is?
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I can simply cut a "Waldo-sized" hole in a big blanket, then position the "Where's Waldo" puzzle under the blanket with Waldo showing through the cut. Easy to do since I know where Waldo is, but impossible to get information from. (At least, theoretically).
- Evbn 14y agoBreaking a glass is non-repeatable, which loses a key aspect of hashing.
- learc83 14y agoOk how about the classic mixing two colors together.
- Evbn 14y agoIf you are only thinking of physical processes and non-expert technicians,and mathematically simulating the inverse is not accepted, yes. It is a good example for lay people not in the paint/color/physics industry.
- kaoD 14y agoThen just cutting a paper in half will do.
- kibibu 14y agoMy first eye-opener about 1-way functions is this algorithm: Take a word. Remove every second letter. This is a one-way function, because it's basically impossible to recover the original, even for two letter words. It's not a very good as a one way hash, because you can trivially construct collisions. It does, however, nicely capture the idea that you are pretty much always going to be discarding information to get a hash (if the hash is shorter than the input), without really resorting to the pigeonhole principle.