Distributed Secure Data Sharing Method for Internet of Vehicles Based on Homomorphic Hash Tree

Data sharing among vehicles is an effective way to alleviate the communication pressure on the backbone network and improve data transmission efficiency in the Internet of Vehicles (IoV). Due to the limited storage capacity of collaborative vehicles, a single vehicle cannot fully store large files or programs such as firmware upgrade packages or ultra-high-definition videos. The current solution is to split the large files that need to be shared into several smaller files and store them in different vehicles for decentralized downloading. However, the current file segmentation methods lack flexibility and cannot effectively address the inherent data consistency and copyright protection issues in distributed storage. Aiming at the above problems, this paper introduces the homomorphic hash algorithm into the IoV and proposes a distributed storage secure data sharing method based on a homomorphic hash tree structure. With the help of layer-by-layer segmentation of the cloud service platform and edge server, the method flexibly divides large files into smaller file blocks and stores them in the sharer vehicles (sharer). The requester vehicle (requester) collaborates with data sharers to obtain all partial data blocks and eventually reconstruct the complete file. Considering the copyright protection problem involved in the file block sharing process, a one-way proxy re-encryption algorithm is proposed to encrypt and share the file core block to ensure that only the paid vehicle can decrypt it using its private key. Through theoretical proof and experimental verification, the method significantly improves the efficiency of data sharing in the IoV and successfully solves the data consistency and copyright problems in the process of distributed storage and secure data sharing.