The 5th International Workshop on Application Intelligence and Blockchain Security (AIBlock)

Keynote: Dr Zhiguo Wan

Title: How to Protect Data Feed to Smart Contracts with Authenticated Zero Knowledge Proof

Abstract: The emerging blockchain technology, combined with the smart contract paradigm, is expected to transform traditional applications with decentralization. When the blockchain technology is applied to decentralize traditional applications, blockchain validators may need to take in sensitive off-chain data to execute a smart contract. On the one hand, decentralized applications (DApps) require authentic off-chain input data to correctly execute a given business procedure. On the other hand, users are reluctant to expose their sensitive privacy on the blockchain. For example, for a decentralized medical insurance DApp that takes as input personal health data, it is critical to guarantee authenticity and privacy of the data sent to the smart contract, such that the data can be verified by validators without leaking sensitive information. However, no satisfactory solution has been proposed to attain privacy and authenticity at the same time.

In this talk, we first present a highly efficient authenticated zero knowledge proof protocol called zk-DASNARK by extending the classical zk-SNARK scheme with data authentication. Based on zk-DASNARK, we design zk-AuthFeed, a zero-knowledge authenticated off-chain data feed scheme to achieve both data privacy and authenticity for blockchain-based DApps. Following the strategy of ''compute off-chain and verify on-chain'', zk-AuthFeed can significantly reduce computation cost of blockchain validators.

Bio: Dr. Zhiguo Wan is Deputy Director and Principal Investigator of Research Center for Intelligent Computing Basic Theories, Zhejiang Laboratory. His main research directions include blockchain, cloud computing, big data, IoT security and privacy protection. He got his Bachelor degree from Tsinghua University, Ph.D. of School of Computer Science from National University of Singapore, and was a post-doctoral fellow in University of Leuven, Belgium. As the project leader, he has undertaken four projects of the National Natural Science Foundation of China, as well as a number of projects such as major basic research projects of the Natural Science Foundation of Shandong Province, and the Ministry of Education's overseas returnee fund project etc. He has published more than 60 academic articles, including INFOCOM, IEEE TDSC, IEEE TIFS and other top international conferences and international journals. His papers have been cited more than 3,000 times, and one of them has been cited more than 600 times according to Google Scholar.