| As cloud computing technology matures,data cloud storage can help people store and share data anytime,anywhere,making data flow more convenient.However,frequent data leakage incidents indicate that data security issues cannot be ignored,how to store and access data safely is an important research topic.With the rapid development of blockchain technology,decentralized data storage become possible.The decentralized storage mode can solve the single point failure problem in the current cloud storage.Compared with the centralized storage mode,it also has a series of advantages such as low price and high throughput.In addition,the blockchain maintains a tamper-resistant transaction log with transparency,unforgeable and falsified information,and anonymity.Combined with the blockchain technology,there are new solutions for the secure storage and sharing of data.This paper makes an in-depth study on the application of blockchain technology in the direction of data security storage and sharing.The main work is as follows:1、A framework combining decentralized storage system IPFS,Ethereum blockchain and attribute-based encryption technology is proposed.In this framework,data owners have the ability to generate keys for users and encrypt their own data by specifiying access policies,enabling fine-grained access control of data.At the same time,based on the smart contract deployed on the Ethereum blockchain,the keyword search function on the ciphertext in the decentralized storage system is realized,which solves the problem that the cloud server in the traditional cloud storage dishonestly returns the search result.Finally,we simulated the solution in the Linux system and the Ethereum official test network Rinkeby environment.The experimental results show that our solution is feasible.2、In order to solve the problem of information island dilemma and medical data storage and sharing in the medical industry,we propose a blockchain-based medical data secure storage and sharing scheme based on the Consortium(Permissioned)blockchain technology.In this scheme,the patient encrypts the medical records and stores them in the chain,and records corresponding related information in the blockchain,and realizes access control and history review through the tamper-resistant data chain records provided by the blockchain.Features.To help patients manage keys more efficiently,we use a tree-shaped key structure that allows patients to remember a master key and generate subkeys to encrypt the data.Finally,we built a 7-node Quorum Consortium Blockchain on Tencent cloud host,deployed smart contract simulation transactions on it to verify the correctness and feasibility of the solution,and gave a functional and security analysis. |
