Zero Knowledge Proof: Explain it Like I’m 5 (Halloween Edition)
Zero Knowledge Protocol ( or Zero Knowledge Password Proof ) is a way of doing authentication where no passwords are exchanged, which means they can not be stolen. The very term “ zero cognition ” originates from the fact that no ( “ zero ) information about the secret is revealed, but the moment party ( called “ Prover ” ) is convinced that the first party knows the privy in question. ZKP allows you proving that you know some secret ( or many secrets ) to person at the other “ end ” of communication without actually revealing it . Explaining crypto is unvoiced, explaining crypto in simple words is harder. Explaining Zero Knowledge Proof to a child ? easy ! so here you go — ZKP explained with some Halloween sugarcoat. previously in the series : Explain Like I ’ megabyte 5 : throughout encoding
Zero Knowledge Protocol
Zero Knowledge Protocol ( or Zero Knowledge Password Proof, ZKP ) is a way of doing authentication where no passwords are exchanged, which means they can not be stolen. This is cool because it makes your communication so fasten and protected that cipher else can find out what you ’ re communicating about or what files you are sharing with each other. ZKP allows you proving that you know some secret ( or many secrets ) to person at the other “ end ” of communication without actually revealing it. The very term “ zero cognition ” originates from the fact that no ( “ zero ” ) data about the secret is revealed, but the moment party ( called “ Verifier ” ) is ( rightfully ) convinced that the first gear party ( called “ Prover ” ) knows the hidden in question. Why would you need to prove you know the privy without telling it ? When you don ’ thyroxine entrust the early person, but even need to persuade them that you know it. so what does the march look like ?
Candy bars and millionaires
Let ’ s exemplify it with the help of Bob and Alice who got some chocolate bars for Halloween . They would like to know if they received the same measure of candy, without disclosing their numeral of chocolates because they don ’ deoxythymidine monophosphate want to contribution . Let ’ s assume they can have precisely 10, 20, 30, or 40 chocolate bars in their trick-or-treat bags.
Read more: A Few Thoughts on Cryptographic Engineering
To compare the count of chocolate bars they got without sharing the actual act, Bob gets 4 lockable boxes and puts a label in each that says 10, 20, 30 or 40 ( cocoa bars ) . then Bob throws away all the keys except for the key to the box that corresponds to the number of chocolate bars he ’ randomness got ( let ’ s say he has 20 chocolate bars ) and leaves . Alice takes 4 little pieces of composition and writes “ + ” on one of them and “ – ” on all the others . then she slips the “ + ” nibble through a slot into the box with the count that corresponds to the number of candies she ’ sulfur got ( let ’ s say she has 30 candy bars ) and slips the pieces of newspaper with “ – ” on them into the rest of the boxes and besides leaves . Bob returns and opens the one box he still has the winder to — the one that corresponds to the come of sugarcoat he ’ sulfur got — and sees if it contains “ + ” or “ – ” . If it is a “ plus ”, Alice has the same number of chocolate bars in her pocket. If the slickness of paper says “ – ”, it means that they have a unlike amount of candy ( but still will not share with each early ). We know that Bob ’ s bag contains 20 chocolate bars and Alice ’ s — 30 cocoa bars. By opening the box and finding the piece of composition with a “ minus ” on it, Bob learns that he and Alice have different amount of sugarcoat. But he has no way of finding out whether Alice has more or fewer chocolate bars . Alice besides returns and sees that Bob has a piece of newspaper with a “ minus ” on it. so he has a different amount of candy. But both Alice and Bob calm don ’ t know how many cocoa bars each of them has. They lone know that they don ’ t have the same sum. such example, in a slenderly different form, is wide known as Yao ’ s Millionaire ’ mho Problem where two millionaires want to find out if they have the same sum of money without disclosing the demand come. This is one childlike case of how ZKP works.
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