(ELI5) ZK Proofs

Zero-knowledge (zk) proofs are a way for one party (the prover) to prove to another party (the verifier) that they know a certain piece of information without revealing the actual information to the verifier. This is useful in situations where the prover wants to prove that they know a secret without actually revealing the secret.

To understand how zk proofs work, consider the following example:

Alice wants to prove to Bob that she knows the password to a certain door, but she doesn’t want to reveal the password to Bob. She could simply tell Bob the password, but then Bob would know the password and could potentially use it to gain access to the door. Instead, Alice can use a zk proof to prove to Bob that she knows the password without revealing the actual password to him.

Here’s how it works:

1. Alice and Bob agree on a set of rules for the zk proof. These rules specify how the prover (Alice) can prove that she knows the password without revealing the actual password to the verifier (Bob).
2. Alice generates a zk proof using the rules agreed upon in step 1. The zk proof contains a series of mathematical calculations and transformations that prove that Alice knows the password without revealing the actual password.
3. Alice sends the zk proof to Bob.
4. Bob verifies the zk proof using the rules agreed upon in step 1. If the zk proof is valid, Bob knows that Alice knows the password without actually knowing the password himself.

In summary, zk proofs are a way for one party to prove to another party that they know certain information without revealing the actual information. This is useful in situations where the prover wants to prove that they know a secret without actually revealing the secret.