What is Zero-Knowledge Proof and Why is it Important to Web3?

Before we get into what Zero-Knowledge Proof is, let’s make sure that we understand the meaning of proof. Proof is the basis of mathematics and how we know that something is absolutely true.

For example, we know that every sum of a triangle’s angles is 180 degrees and we can prove it, therefore we know that to be true for every triangle.

Proofs are what allow us to be certain about mathematical facts. If someone wants to verify that a triangle’s angles add up to 180 degrees, then they can follow the correct steps of the formula which will result in the correct answer, aka the truth.

This person would be known as a verifier, and the person who originally created or holds the formula to solve the equation would be known as the prover.

Zero-knowledge proof is a process through which the prover may show to the verifier that a particular claim is true without providing any extra information other than the fact that the statement is true.

The idea of zero-knowledge proof is that it’s straightforward to demonstrate knowledge of some information simply by exposing it; the obstacle is to prove such knowledge without disclosing any extra information.

Since proving a statement demands that the prover holds some secret knowledge, the verifier will be unable to prove the statement to anyone else unless the prover possesses the hidden information.

The claim that the prover knows such information must be included in the statement being proven, but the information itself doesn’t need to be included or communicated in the claim.

Immersive zero-knowledge proofs need interaction between the person (or system) proving their knowledge and the person confirming the proof.

A protocol that implements zero-knowledge proofs must call for direct input from the verifier. This interactive input is often in the form of one or more tasks, with the prover's replies convincing the verifier only if and when the assertion is true.

Zero-knowledge proof is important because it allows the prover to relay the truth of a specific piece of information to the verifier without disclosing any more information than necessary. 

The greatest concern in transacting on the blockchain is the multiple flaws that may be found in traditional approaches. When zero-knowledge proof is combined with private blockchain transactions, they become resistant to hacking or interception.

Here are three main reasons why zero-knowledge proof is so important:

1. Validity: If a statement is true then the verifier can confirm the prover possesses the required information.
2. Trust: The statement cannot be fake, and the verifier cannot be convinced the prover has the required information when they really don’t.
3. Zero-knowledge: The verifier will have no knowledge of anything other than whether the claim is true or false. The information and personal data of the other parties are kept private.

Overall, zero-knowledge proof ensures that both parties in a transaction remain safe and trustworthy, otherwise the transaction can’t be completed.

As you can see, zero-knowledge proof is very beneficial to keeping privacy a priority, while still maintaining the trust and transparency that the blockchain is known for. So what is an example of zero-knowledge proof being implemented on the blockchain?

Zcash is one example of zero-knowledge proof used on the blockchain. Zcash is a cryptocurrency that leverages zero-knowledge proof. Zcash developers created their own technology known as zk-SNARKs, which allows users to choose privacy when trading with the cryptocurrency.

zk-SNARK is an abbreviation for Zero-Knowledge Succinct Non-Interactive Argument of Knowledge, and it refers to a proof development in which one can prove ownership of certain information, such as a secret key, without revealing the key or requiring any interaction between the prover and verifier. 

These proofs are not only safe, but they are also extremely quick with a verification time of only a few milliseconds. 

Personal privacy has been a major element of the blockchain and cryptocurrency revolutions, and zero-knowledge proof combined with zk-SNARK technology is prepared to continue on this quest for trust and efficiency on the blockchain.