Abstract: To solve the problems of over-centralized data storage and low utilization efficiency in online shopping， this paper proposes a decentralized online shopping data sharing scheme based on blockchain. Firstly， SM2 elliptic curve public key cryptography algorithm and smart contract technology are used to encrypt and store online shopping data to ensure data integrity and security. Secondly， smart contract binding technology and SimHash technology are used to collect and process online shopping data to ensure data authenticity and improve data quality. Finally， the improved ZK-PoD （Zero Knowledge Proof of Delivery） protocol is used to realize the sharing of online shopping data， so as to achieve the fair exchange of data and value without the participation of trusted third parties. Theoretical analysis and experiments show that this scheme is more secure than traditional centralized online shopping data management scheme. Compared with the data sharing scheme implemented by proxy re-encryption technology， this scheme greatly reduces the time required for data sharing.

Key words: blockchain, data sharing, smart contract, online shopping