Zhongan Technology Wu Xiaochuan: Blockchain+ composite technology can better protect data privacy

[Mixed Chain Pulse Press] : In 2017, we will talk about the certificate and 2018 about performance. By 2019, almost all formal blockchain conferences will talk about privacy.

In the words of Wu Xiaochuan, Zhongan Technology, privacy is a topic that cannot be avoided in the blockchain. Libra was questioned by the US Congress because of privacy issues; many projects are timid; the ideal of digital citizenship has not yet been realized…

In July of this year, the China Electronics Technology Standardization Institute of the Ministry of Industry and Information Technology issued the "Guide to the Blockchain Privacy Computing Service", which is likely to affect the development of China's blockchain privacy technology. Zhongan Technology participated in the compilation of the guide. On September 18th, Wu Zhongchuan, director of Zhongan-Fudan Blockchain and Information Security Joint Lab, accepted an inter-chain pulse interview in the office of Zhongan Technology.

(Zhong Xiao, Director of the Joint Lab of Blockchain and Information Security, Fudan District)

Mutual chain pulse: This year we noticed a significant increase in privacy technology mentioned in the blockchain field. What is the reason?

Wu Xiaochuan: Privacy is a topic that cannot be avoided in the large-scale blockchain. As long as the blockchain is to be applied on a large scale, privacy protection will definitely be put on the table. The reason is that the blockchain has the characteristics of decentralization and transparency. Users will worry about how well my data is protected.

The development of technology is often due to the demand for landing scenes. This year, people mentioned more privacy, which is also due to the application landing. For example, Zhongan Technology proposed to use the Open Assets Agreement (OAP) to enjoy the policy of insurance policy, and to pass the insurance policy in the insurance field, so that the policy can be safely re-guaranteed, and this requires privacy protection.

In other scenarios, there are certainly privacy issues that cannot be circumvented. From a technical point of view, it is more challenging than the traditional centralized protection of users' privacy schemes. Why are you welcoming this challenge? The development of blockchain technology has improved the efficiency and credibility of data exchange between different organizations to a certain extent, providing a new paradigm for data sharing. The blockchain can realize multi-party collaborative data calculation under the premise of protecting data privacy, and improve data utilization efficiency. This is a bad thing to do with centralized data.

Mutual Chain Pulse: We also know that Zhongan Technology has participated in the compilation of the Guide to Blockchain Privacy Computing Services. What do you think is the meaning of the guide?

Wu Xiaochuan: We always say that data is the current oil, but how to use the value of the data, while not invading the data, let the data flow, breaking the data island is what we are trying to explore. But how to use the data, how to use the value of the data, and then play the value of the data, but also better protect user privacy. So this is one of the meanings.

The other one, in fact, I just said that the blockchain's open and transparent nature determines that it needs to have higher requirements for privacy protection, and it also poses a big challenge. The guide hopes to give you some technical solutions to make the blockchain privacy technology fall as soon as possible.

Inter-Chain Pulse: What specific support does Zhongan specifically provide in the preparation of the Guide to the Blockchain Privacy Computing Service?

Wu Xiaochuan: Zhongan Technology deeply participated in the preparation of this guide. In fact, in 2016, Zhong An established a cryptography laboratory with Fudan University. It is a laboratory for blockchain and information security. One of the purposes of the laboratory is to let cryptography go out of the laboratory. Apply to the commercial landing, play the value of cryptography. Cryptography and blockchain are a very good combination of scenarios, so in this guide, Zhongan Technology is more involved in the design and optimization of cryptographic algorithms, such as algorithm optimization for zero-knowledge proof.

Mutual chain pulse: We have noticed that the Guide has the existence of regulators and auditors. On the one hand, we advocate privacy protection, on the other hand, we must supervise and audit data. Is there a contradiction?

Wu Xiaochuan: Any industry needs supervision and auditing, which is for compliance and security. This requires a trade-off between privacy and regulation.

I think there is no contradiction between them. First of all, data privacy is more concerned with some of the individual's data information, while supervision and auditing are more concerned with industry-level compliance. For example, blockchain is a point-to-point exchange of information. In peer-to-peer transactions, users want to protect their privacy, but this may create financial risks. Such as money laundering. Therefore, in special circumstances, regulators must exercise the right to supervise.

For technology, this needs to be considered at the beginning of the system design. This is also the necessity of supervision and auditing in the Guide. If it is not considered beforehand, then like the governments we see now, we are holding digital currency. There is a questioning attitude because it has a lot of financial risks.

Mutual Chain Pulse: We saw a lot of privacy protection techniques mentioned in the Guide, such as zero-knowledge proof, ring signature, and homomorphic encryption. Which one do you personally like? Still think that privacy protection should be a relatively complex technology?

Wu Xiaochuan: I agree with the combination of blockchain , artificial intelligence, and Internet of Things to protect privacy.

Focusing on the blockchain, all information is public and transparent. Some parties only want the transaction parties to see the specific content of the transaction, and do not want the content of the transaction to be leaked to other people who have the right to view the books, but in the blockchain. It is also necessary for the consensus to check the consensus and how to verify the privacy transaction. Then naturally, I think of the zero-knowledge proof. Just when you mentioned the ring signature, the ring signature and the zero-knowledge proof have different effects. Our team is paying attention to the common ways of zero-knowledge proof in several blockchains, zk-snark, zk-stark, bulletproof. These methods are used in some projects but because they involve many mathematical theories, many complicated mathematical formulas, The algorithm has not yet been applied on a large scale, and is limited by the scene, the amount of calculation, the size of the transaction, and the threshold of knowledge.

Our lab has optimized the key-generation and sub-algorithms in zk-snark. Now we are considering the problem of using hardware parallel acceleration to solve complex computational gates. Now we can speed up more than 100 times faster than previous methods. .

Mutual chain pulse: Zhongan Technology has made great breakthroughs in privacy protection technology. Is there any practical application?

Wu Xiaochuan: As mentioned earlier, the composite technology protects data privacy. In October last year, we also mentioned the concept of a cryptographic neural network, combined with federal learning and data computing, to achieve multidisciplinary cross-protection of data privacy, making user data available invisible, open but not shared.

Mutual chain pulse: This sounds great. Can you tell us more about it?

Wu Xiaochuan: The artificial intelligence training model can be transmitted through the blockchain , and the automatic modeling and learning in the data side, and then the encryption and calculation technology will be used to encrypt and calculate the entire learning process. The data will not be leaked to any party, and the data will be “open”. But it does not share, and based on decentralized and non-tamperable features, it brings a new definition to cryptography; cryptographic algorithms ensure data privacy on the blockchain, open up data islands, and realize data circulation value.

Mutual chain pulse: What kind of scene will it use?

Wu Xiaochuan : There is a very classic example. For example, every mobile phone input method and expression in the mobile phone, how do we let the input method help us automatically arrange the expression position according to personal habits, usually the backend service can collect user habits, and then help User-defined rules, but we now want to let the data learn at the terminal by not collecting user terminal data. At the same time, the terminal can issue general data or noise-added data to the service provider through the encrypted computing network for the service provider to enhance the modeling. Feed back to the terminal, which is also a kind of edge calculation.

Mutual chain pulse: Under this understanding, what do you think is an indicator of the maturity of privacy protection technology?

Wu Xiaochuan: Privacy protection, there is currently no relatively mature general indicator. As we write the guide, there is no standard to be met by the default technology. But I think that technology can be considered a mature indicator for large-scale commercial use. Privacy protection technology may actually be more commercial than ordinary technology, so that users are not aware, so that this developer can be very easy to get started, the development threshold is very low, so mature.