Zero-Knowledge Proof: The ‘Swiss Army Knife’ of Privacy Tech


by Jinghui Liao, Core Developer, Neo

When it comes to our own personal information, such as banking data or health records, there is no question; We expect privacy. The conversation around blockchain privacy is gaining traction. While transparency is one of the underlying principles of blockchain, whereby all information must be open-source and readily available, the question of privacy for both individuals and institutions must be addressed before mass adoption can take place.

However, it is not always an easy task to display the evidence while maintaining confidentiality. Fortunately, zero-knowledge proofs (ZKP) have demonstrated significant utility for the blockchain space and are rapidly generating interest across the sector, with several inherent benefits for the ecosystem.

Fundamentally, the ZKP system is a method by which one party (the ‘proposer’) can prove to another party (the ‘verifier’) that a given statement is true, while the ‘provider’ is free to communicate any additional information. avoids. To use a scenario from everyday life, if you need to prove that a lost phone is indeed yours, you can provide proof of ownership by unlocking the phone with Face ID. During this process, you will not disclose to the searcher any password or other information from which the ZKP can be directly accessed.

While the example above shows a simple example, we can see how this applies to specific cases within blockchains:

Privacy protection

In traditional blockchain transactions, the information of the participants is publicly accessible. All transactions are recorded on a public ledger, which may pose privacy or security risks. Therefore, to protect the privacy of participants, transactions need to be completed in a way that does not reveal their personal IDs.

ZKPs provide a solution by proving transactions without the need to publish any sensitive information on the blockchain, enabling secure and anonymous transactions when necessary. Multiple types of ZKPs can enable authentication without revealing sensitive information, with the end result being a higher level of privacy and security. For example, a zk-SNARK obscures transaction amounts to protect user privacy and makes it impossible for individual users to link certain transactions.

id authentication

When online, users must often provide personal information such as their name, address, phone number, etc. to verify their identity, which risks compromising their privacy. As an alternative, ZKP allows users to verify their identity without revealing any sensitive information.

One example is the non-profit ID2020, which is dedicated to providing digital identities for those who do not have access to ID cards and may face difficulties accessing basic rights and services as a result. ID2020 uses ZKP technology so that people can verify their identity anonymously without providing sensitive information like their name, address etc.

protect sensitive information

For corporations and businesses, sharing sensitive information can have catastrophic effects. However, ZKPs can help protect against this.

For example, a company may use ZKPs to prove that it has reached required sales thresholds to suppliers or investors, without disclosing the specific (confidential) data involved. This ‘anonymous information’ sharing has a wide range of applications in supply chain management, medical record sharing, insurance claims and many more.

Another use case is for data verification, whereby some blockchain applications may set a certain limit for users to transact and, in order to continue using these platforms, users must prove that they have specific data points. which are personal to him.

ZKP allows users to verify whether a given data point satisfies a certain condition. For example, a user may need to prove that they own a certain amount of cryptocurrency, and ZKP allows the user to do so without requiring the user to disclose the actual amount.

property ownership

This can also be extended to copyright protection, allowing owners of digital assets such as music, video or software to prove ownership without making the details of those assets public, thereby protecting against piracy or infringement of intellectual property rights .

As an example, Verisart is a blockchain-based digital artwork authentication platform that uses ZKPs to prove ownership of digital artworks. When an artist uploads their art, Verisart uses ZKP technology to generate a mathematical proof of ownership without revealing any sensitive information.


In the traditional voting process, votes are cast publicly, with participants placing paper votes in a sealed box. While it maintains a certain amount of privacy, voters’ choices can be influenced and the system is not suitable for long-distance voting.

ZKPs are widely used for those casting votes in Decentralized Autonomous Organizations (DAOs), and can also be used in places where voters feel threatened or influenced to vote a certain way. There are Essentially, ZKPs ensure that voters can prove their ballots are valid without the need to reveal their identity, as well as preventing voters from acting maliciously (trying to sell ballots, voting multiple times, etc.). via) also provide protection against.

In summary, the ZKP technique is an important, privacy-preserving technique that can prove the correctness of a fact without revealing the information on which the proof depends. In blockchain, ZKP technology has a multitude of uses for ensuring privacy protection, identity authentication, and secure sharing of information. In all of these use cases, and many more, ZKPs can help ensure the privacy and security of users while facilitating the development of blockchain technology in a wide range of scenarios.

ZKP ensures privacy for users when privacy is needed. And, when privacy is required, we expect it.

The views and opinions expressed here are the views and opinions of the author and do not necessarily reflect those of Nasdaq, Inc.

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