Research on Security Algorithm of Cross-Cloud Data Sharing Supported by Blockchain

In order to improve the security and privacy of data sharing, this project intends to study a data sharing security algorithm based on blockchain in a cross-cloud computing environment. The security algorithm that integrates cryptography and smart contracts is studied to ensure that data is effectively encrypted during the sharing process, and to ensure the execution efficiency and effectiveness of smart contracts under the dynamic changes of the sharing parties. Then this paper uses hash functions, symmetric and asymmetric encryption methods to improve the secure transmission of data. In the simulation experiment, this paper will compare the differences in data integrity, privacy and operating efficiency of various cryptographic algorithms, as well as their adaptability in a cloud computing environment. The experimental results show that compared with traditional methods, the encryption and decryption speed of the algorithm can be increased by about 15%, and the execution efficiency of smart contracts can be increased by about 12%.