What is Zero Knowledge Proof (ZKP) and Privacy Benefits?

What is Zero Knowledge Proof (ZKP)?

Zero Knowledge Proof (ZKP) is a sophisticated cryptography method in which data is coded to enable verification without actually revealing the data or its details. The encryption method offers several benefits and has plenty of real-world use cases.

With the advancement in the crypto landscape, privacy and security have become more important than ever. Stakeholders are now looking for new and reliable ways to ensure privacy and security while maintaining blockchain’s decentralization.

What is a Zero-Knowledge Proof (ZKP)?

Zero-knowledge proof is an encryption method that generally involves two parties: the prover and the verifier. The technique allows the prover to prove to the verifier that the former has some information without actually revealing it.

Moreover, the proofing is done in such a way that the verifier is also fully assured that the prover has accurate information.

For example, suppose you are the head of a group that safeguards a vault with a combination lock, and a strange man approaches you and says that he is also a part of your group. To verify the claim, you place a secret message and keep it in the vault.

If the strange man, the prover in this case, is really a member of your group, he would know the combination to open the vault, be able to open the vault, and tell you (the verifier) the secret message you wrote. This way, you can verify the authenticity of that person’s claim without actually revealing the vault’s combination.

ZKP in crypto

Crypto projects have already integrated ZKP into their chains. Ethereum, one of the top cryptocurrencies favored by whales at this time, may have its own zero-knowledge proof (ZKP), known as GKR (for the tech-savvy, GKR does not handle privacy unless it is wrapped by ZK-SNARK).

Vitalik Buterin, the co-founder of ETH, suggested implementing GKR to accelerate the network.

In May 2025, Google adopted ZKP, blockchain tech, to its Wallet app for digital IDs. The technology may be adopted by more brands (and potentially governments) and future blockchain chains.

How does Zero Knowledge Proof work?

A 1985 MIT paper titled The Knowledge Complexity of Interactive Proof-Systems first described zero-knowledge proofs. The paper demonstrated that a prover can convince the verifier about the authenticity of the data without revealing any additional information about the data.

The ZKP process involves the verifier asking the prover to perform certain actions. The prover can only accurately perform those actions if he knows the underlying information.

It must be noted that the successful working of ZKP depends heavily on mathematical constructs, including probabilistic algorithms, cryptographic hash functions, and randomness. The use of mathematical constructs also ensures that there are no information leaks during the verification process.

Zero Knowledge Proof privacy benefits

Zero-Knowledge encryption offers several benefits:

Enhances and preserves privacy by allowing people to prove the possession of information without revealing key details.
Helps institutions meet the privacy requirements by minimizing exposure to key information. For instance, the United States’ Health Insurance Portability and Accountability Act (HIPAA) requires companies to protect the Personally Identifiable Information (PII) of their customers.
Boosts trust in online transactions and communications by allowing verification without revealing full information.
Reduces the risk of data breaches by eliminating the need for sharing key information.
Can be easily applied across several areas, including authentication systems, secure communication channels, and blockchain.

Other use cases for ZKP

Zero knowledge protocol has several use cases across many benefits. Some of the key zero-knowledge proof applications are:

Blockchain

ZKP is helping users to store their cryptocurrencies safely while keeping the general ledger details public. Furthermore, it is also helping blockchain projects to boost scalability by allowing computing off the chain, while still being auditable on the chain
Ethereum coin, for instance, is already using the ZKP protocol to minimize computations and improve privacy.

Biometric and password authentication

Businesses and institutions can deploy ZKP to verify biometric data, such as facial or voice recognition, without revealing the raw biometric details. For instance, a person can prove they have a valid face for authentication without revealing their face.
Similarly, websites and apps can use the ZKP to verify the login details without users actually transmitting passwords over a network.

Voting systems

Preserving a vote’s secrecy is the biggest challenge in electronic voting, and ZKP can easily help with it. A ZKP-based voting system would allow users to cast valid votes without linking them to the voters’ identities. Many countries are already exploring such a voting system to revolutionize their election processes while preventing electoral fraud.

Age and credentials verification

ZKP can easily allow individuals to prove they are above a certain age without revealing their exact birth date. Similarly, the encryption method can be used to verify credentials such as educational degrees or professional certifications without requiring individuals to disclose specific qualification details.
For instance, companies can deploy ZKP to verify a job applicant’s age and other qualifications without requiring them to reveal all details.

KYC requirements

Banks and other financial institutions can deploy ZKP to complete Know Your Customer (KYC) requirements without requiring users to share sensitive personal information. For example, users can prove that they fulfil key KYC requirements, such as citizenship, without revealing their full national identity number and complete address.

Types of Zero-Knowledge Proofs

There are two main types of zero-knowledge proof, depending on how they demonstrate knowledge without disclosing information.

Interactive Zero Knowledge Proof

Interactive ZKP requires the verifier to constantly interact with the prover to verify the knowledge possession. The verifier asks questions or poses challenges, and the prover has to act or answer accordingly to convince the verifier.

Such a ZKP is suitable for projects where both parties are actively engaged in the verification process. However, the need for constant communication makes it less practical for large-scale applications.

Non-interactive Zero Knowledge Proof

Non-interactive ZKP doesn’t require an interactive process; rather, one round of communication between the prover and verifier is enough for verification. Such a type of ZKP is more efficient and scalable, making it a better choice for large-scale projects.

Under non-interactive, the prover generally provides proof based on public information that can be easily verified without further interaction between the prover and verifier.

ZK-SNARKs and ZK-STARKs are two popular types of Non-interactive ZKP. ZK-SNARKs (Zero-Knowledge Succinct Non-Interactive Arguments of Knowledge) include short proof sizes and quick verification times, while ZK-STARKs (Zero-Knowledge Scalable Transparent Arguments of Knowledge) eliminate the need for a trusted setup, and thus, offer more scalability and security.

Zero Knowledge vs Zero Trust

Zero Knowledge Proof (ZKP) and Zero Trust are separate concepts but have some similarities. ZKP, as detailed above, is a cryptographic protocol that allows one party to convince the other that the former possesses the information without actually revealing that information.

Zero Trust, on the other hand, is a broader term that may include ZKP. It is a general cybersecurity model or a security framework that entities deploy to safeguard their valuables, including data, premises, and other resources.

Zero Trust works by assuming that every entity is a threat. Thus, the security framework requires every user and device to be authenticated and continuously verified before granting access to resources.

Summary

Zero-knowledge proofs are an exciting frontier in blockchain technology with immense potential and a wide variety of applications. Understanding how Zero-Knowledge Proof works gives entities a reliable way to deal with untrusted or unidentified parties.

To get the best results, it is important for entities to combine the privacy-preserving design of ZKP with blockchain’s inherently transparent nature. Moreover, it is also vital for organizations to integrate ZKP seamlessly with existing systems and processes.