With information leakage incidents becoming common, whether stored on the Internet or in offline archives, information security issues have become an urgent challenge. As long as information is stored centrally, there is a risk of being attacked by a single point; as long as verification requires a trustworthy third party, it will bring about moral hazard and efficiency issues. Solving information security issues is crucial, and zero-knowledge proof technology provides users with the opportunity to complete verification more efficiently and securely while protecting privacy.
If Bitcoin is the first invention that blockchain has brought to the real world, providing a new way to store value; Ethereum’s smart contract is the second major milestone, unleashing the potential for innovation. Then, the application of zero-knowledge proof can be regarded as the third major technological innovation in the history of blockchain development, which introduces privacy and scalability into the blockchain world. Zero-knowledge proofs are not only an important part of the Web3 ecosystem, but also a key technology for potential social change.
This article is written from the perspective of a non-technical person and aims to introduce the application scenarios, working principles, development status, and future trends of zero-knowledge proof, so as to help readers without a technical background gain a deeper understanding of the major changes that zero-knowledge proof may bring.
1. What is zero-knowledge proof?
Zero-knowledge proof (ZKP) was first proposed by Shafi Goldwasser, Silvio Micali and Chales Rackoff in 1985. It is a mathematical protocol that does not reveal any other information except proving the authenticity of a certain fact. In a zero-knowledge proof, the verifier does not have access to the secret information needed to generate the proof. To explain with a simple example: If I want to prove that I know someone's phone number, I just need to dial that person's number in front of everyone without revealing their real number. Zero-knowledge proofs provide an almost risk-free way to share data. Through zero-knowledge proof, we can retain the ownership of the data, significantly improve the level of privacy protection, and hopefully make the problem of data leakage a thing of the past.
Zero-knowledge proof has the following three characteristics:
Completeness: If a statement is true, an honest verifier will be convinced by an honest prover.
Plausibility: If a claim is false, a cheating prover cannot in the vast majority of cases convince an honest verifier of the false claim.
Zero-knowledge: If a statement is true, the verifier does not gain any additional information other than knowing that the statement is true.
Zero-knowledge proofs have a very small probability of reasonableness error, that is, a cheating prover may make the verifier believe a wrong statement. Although zero-knowledge proofs are probabilistic rather than deterministic, we can reduce the reasonableness error to a negligible level through some techniques.
2. Application of Zero-Knowledge Proof
Zero-knowledge proof has two important application scenarios: privacy and scalability.
In terms of privacy, zero-knowledge proofs allow users to safely share necessary information to obtain goods and services without revealing personal details, free from the threat of hacker attacks and personal identity information leakage. With the integration of digital and physical fields, the privacy protection function of zero-knowledge proofs is essential for information security in Web3 and other fields. Without zero-knowledge proofs, user information may be stored in trusted third-party databases and face potential hacker attacks. Privacy coin Zcash is the first application case of zero-knowledge proofs in blockchain, which is used to hide transaction details.
In addition, zero-knowledge proofs can also be used to build decentralized identity systems that enable users to control access to their personal identities without revealing sensitive information. This identity system can be used for purposes such as citizen identity verification, simplifying the authentication process and reducing the problem of users losing access due to forgotten passwords.
Another important application is to build private reputation systems, which allow service agencies to verify whether users meet certain reputation standards without revealing their identities. Users can anonymously export their reputation from the platform without revealing the specific source account.
3. How Zero-Knowledge Proofs Work
The structure of zero-knowledge proof can be divided into two types: interactive and non-interactive.
This process can be repeated multiple times until the prover is able to generate a proof that the verifier accepts without knowing the secret information.
Non-interactive zero-knowledge proofs (NIZKs): NIZKs allow the prover to generate a proof once and send it to the verifier without further interaction. NIZKs are often constructed using mathematical tools such as elliptic curve cryptography and zero-knowledge proof systems. This form of zero-knowledge proof is often more efficient, but its security often depends on the strength of the underlying cryptography.
4. Current Status of Zero-Knowledge Proof
Zero-knowledge proof technology has made significant progress in multiple fields. Here are some current ongoing efforts and projects:
zk-SNARKs (Zero-knowledge scalable non-interactive parameterized knowledge proof): zk-SNARKs is a very efficient zero-knowledge proof system that has been widely used on blockchain platforms such as Ethereum. They enable highly compressed proofs, significantly increasing blockchain scalability.
zk-STARKs (Zero-Knowledge Scalable Recursively Parameterized Proofs of Knowledge): Unlike zk-SNARKs, zk-STARKs do not rely on trusted set parameters and are therefore more decentralized and secure. They may be slower than zk-SNARKs in some cases, but have stronger security.
zk-Rollups (Zero-Knowledge Scalability Solution): zk-Rollups are a method of improving the scalability of blockchains such as Ethereum by moving transactions and computations off-chain. They use zero-knowledge proofs to ensure security and consistency on-chain, while performing most of the computation off-chain, reducing the load on the chain.
Decentralized identity and privacy protection: Many projects are developing decentralized identity systems to provide users with better privacy protection and identity control. These systems use zero-knowledge proofs to verify identity information without exposing details to third parties.
5. Future Trends of Zero-Knowledge Proof
Zero-knowledge proof technology is expected to continue to develop in the next few years and have a wide range of impacts in various fields. Here are some possible trends in the future:
Wider blockchain applications: Zero-knowledge proofs will continue to play an important role in the blockchain field, including privacy coins, scalability solutions, decentralized identity and reputation systems, etc. These applications will help improve the performance and privacy protection of blockchains.
Cross-industry applications: Zero-knowledge proof technology will find wide applications in various industries such as finance, healthcare, supply chain management, etc. For example, in the medical field, zero-knowledge proof can be used to securely share patient data without revealing sensitive information.
Legal and regulatory challenges: As zero-knowledge proofs become more widely used, legal and regulatory issues may raise concerns. How to balance privacy rights and compliance requirements will become an important topic of discussion.
Education and Popularization: The complexity of zero-knowledge proofs makes them difficult to understand and use. In the future, there may be more educational resources and tools to help people understand and apply this technology.
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In conclusion, zero-knowledge proof technology has great potential to change the fields of information security, privacy protection and blockchain. Although there are still some technical challenges and legal issues to be resolved, we can expect to see more innovations and applications of zero-knowledge proof technology as this field continues to develop. This technology is expected to become the third technological revolution in the history of blockchain development, with a profound impact on society and the economy.
