1 Introduction
Currently, the value of zero-knowledge cryptography is still underestimated.
The current media hotspot is still artificial intelligence and machine learning (AI/ML), and little attention is paid to the value of zero-knowledge cryptography.
As more and more social and economic activities occur on the network, more and more data are generated, zero-knowledge cryptography can solve the privacy protection problem in AI/ML algorithms.
For ordinary users, they do not need to know the working principle of zero-knowledge cryptography, but only need to have a basic understanding of the technology to understand why they should pay attention to zero-knowledge cryptography and its breakthrough value.
2. Brief description of zero-knowledge proof
Zero-knowledge cryptography is a very broad subject, and in this article, we only focus on one of its most important areas:
zero-knowledge proof.
Zero-knowledge proof refers to an informal way of a very specific concept in computer science: a non-interactive, zero knowledge argument of knowledge.
In the zero-knowledge proof, there are 2 parties:
- Prover
- Verifier
Prover wants to prove that it knows certain information, which it does not want to disclose to Verifier.
Verifier only needs to check the proof provided by Prover, and then decide whether to accept or reject.
Zero-knowledge proof has three major attributes:
- Completeness——A prover with a witness www for u ∈ L u \in L u∈L can convince the verifier of this fact.
- 可靠性Soundness——即A prover cannot convince a verifier when u ∉ L u\notin L u∈/L.
- 零知识性Zero-knowledge——即The interaction should not reveal anything to the verifier except that u ∈ L u\in L u∈L. In particular, it should not reveal the prover’s witness w w w.
For example:
in a festival interaction, due to the provision of alcoholic beverages, the event organizer requires that the participants must be over 21 years old. When you show up at the entrance, the guard will check your ID to make sure you meet the age requirement. If so, they will give you a wristband. Every time you stop for a drink in front of the booth, the waiter does not need to check your ID. They know that because you have a wristband, you must meet the age requirement.
Of course, there are many ways to deceive or bypass the basic system above. But what if you replace the guard in the above example with a robust encryption protocol based on mathematics? Not only does it make the deception system impossible, but it also works without you having to reveal your age to anyone.
First, prove that the statement ("I am over 21 years old") is true without revealing the underlying facts ("My actual age is 25 years old"). This is a very powerful primitive.
This technology has great potential value not only for individuals, but also for enterprises and governments.
Listed below are the real problems that exist today. Zero-knowledge cryptography can help solve these problems and open the door to new and exciting products and examples.
3. Use cases for zero-knowledge proof
3.1 Zero-knowledge proof is used to protect user data
Zero-knowledge proof can provide consumers with a better and safer network experience. For example, imagine that you only need to use zero-knowledge proof to prove that you meet the loan requirements to successfully apply for a loan without providing other irrelevant identity information. In addition to convenience, this method is also safer.
When the credit rating agency Equifax was hacked in 2017, it exposed the personally identifiable information (PII) of millions of people.
This type of hacking is not an isolated incident, but reflects the widespread problem of today’s networks:
companies that require and store your sensitive personal data (at best) have limited incentives to properly protect your sensitive personal data.
However, a zero-knowledge proof-based system not only reduces the potential liability and cost of storing user data, but also makes the overall online experience of consumers safer.
3.2 Zero-knowledge proof is used for sensitive system or contract audit
From an enterprise perspective, zero-knowledge proof technology can be used to simplify many business interactions and contracts. Imagine that a company has purchased a license for a technology solution, but wants to make sure that it will work as advertised. But suppliers are hesitant to reveal the intellectual property rights that are vital to the product. Using zero-knowledge cryptography, vendors can prove that their products have certain attributes or characteristics without revealing the underlying source code.
Of course, zero-knowledge proof cannot replace the existing corporate legal framework. But they can be supplemented by reducing inefficient and expensive manual verification and auditing. In this way, zero-knowledge proof guarantees the confidentiality of both parties to the transaction without compromising the motto of "trust but verify" ("trust but verify").
3.3 Zero-knowledge proof is used for the fair distribution of public goods
Certain organizations can also use zero-knowledge proofs to prove that they are running processes correctly or distributing goods fairly. For example, universities can show that they have selected the best candidates from a group of qualified applicants without revealing personal test scores or other sensitive personal details. This will enable them to maintain a proprietary and selective process while using zero-knowledge proofs to prove some facts about the selection process and admitted applicants to show that it is "fair."
3.4 Zero-knowledge proof is used to improve the efficiency of bureaucracy and reduce costs
Zero-knowledge proof technology can help NGOs and standards bodies conduct audits in an easier way. One obvious use case is financial auditing.
Zero-knowledge proofs can even be applied to nuclear arms control protocols.
In addition, zero-knowledge proof (combined with blockchain or digital ledger) can provide the government with a more effective mechanism to collect taxes or directly stimulate payments, while ensuring that citizens' privacy rights are still maintained.
4. Why zero-knowledge proof is important
The Internet has affected our society in many ways. One consequence is that as our lives become more and more digital, the information we choose to share becomes more and more important. Because once you post on the Internet or disclose any information about yourself to anyone, it will be difficult for you to hide it.
In the real world, the data we reveal is naturally short-lived, because we can always choose to hide it. But online you can never really know if it has been downloaded and copied by anyone who has seen it. Therefore, even after you delete an article or delete an application, this information may still exist. Regular leaks, hacking attacks, and even surveillance of our data will only exacerbate this danger and show that the existing special privacy rule system is at best a band-aid.
Fortunately, zero-knowledge cryptography provides a possible solution to these challenges. A system in which users of an application prove facts or knowledge without revealing its essence is a truly new paradigm. Combined with modern networks, this technology can make the Internet more convenient, safer, and more powerful than ever before.
Reference
[1] Alex medium blog Zero at The Knowledge Cryptography & the Next Digital Revolution
[2] blog zero-based learning zero-knowledge proof