@Boundless #Boundless $ZKC

Study notes, what is zero-knowledge proof

Example: John and the Halloween Candy

Suppose John claims he knows which pumpkin in his neighbor’s yard has Halloween candy. Mary wants to check if John really knows, but she doesn’t want to find the candy herself or learn its exact location.

Traditional Way

Mary asks John to tell her exactly which pumpkin has the candy.

Problem: Mary now knows the location, so the candy is no longer a secret.

Zero-Knowledge Proof Way

John can prove he knows the candy’s location without revealing it:

1. Mary closes her eyes.

2. John goes to the correct pumpkin, picks up the candy, and then puts it back.

3. Mary opens her eyes and sees that John could find the candy—but she still doesn’t know which pumpkin it is.

Result:

Mary is convinced John knows where the candy is.

Mary hasn’t learned the secret location, so the candy remains safe.

Why Zero-Knowledge Proofs Are Useful

1. Secure: You can prove knowledge or ability without revealing the secret itself.

2. Reliable: Others can trust that you really know or can do something, without taking your secret.

3. Practical Applications:

Finance/Blockchain: Prove you have enough funds without showing your account balance.

Identity Verification: Prove you are over 21 without revealing your birthday.

Privacy Protection: Prove data meets a requirement without sharing the data itself.