Research On Blockchain Data Storage And Cross-chain Communication Mechanism

With the popularization and application of big data technology,the amount of data in various industries is growing explosively.More and more data needs to be stored safely and effectively for users.The traditional data storage mode based on centralization is faced with the problems of high storage cost,low access efficiency and easy to be attacked,resulting in data tampering or destruction.It has been unable to meet the requirements for safe,stable and reliable data storage.Blockchain technology can achieve the purpose of decentralized,trusted and difficult to tamper with data storage without the need for a third-party trust agency.The emergence of blockchain provides a feasible solution for trusted data storage.However,the existing blockchain system has the defects of insufficient storage space on the chain and low overall system performance,which makes it difficult to directly realize the storage requirements for large-scale data.Secondly,blockchain development should aim at different application scenarios and often adopt different development logic,which makes it difficult to carry out inter chain data sharing and cross chain business collaboration.Data sharing is the key to improving data value.In order to solve the above problems,this paper first studies the problem of improving the performance of data storage based on the blockchain system,and proposes a blockchain data storage mechanism combined with the IPFs system to store data through the collaborative data storage scheme on and off the chain,which greatly reduces the data storage pressure in the blockchain system and improves the performance of the blockchain system.Secondly,this paper studies the difficulty of cross chain communication between blockchains,improves the relay based cross chain communication mechanism,and realizes the cross chain asset transfer and cross chain information sharing between different blockchains.The main work and achievements of this paper are as follows:(1)Combine the alliance chain with the IPFS system for collaborative storage of data.First,use a consortium chain with an admission mechanism to restrict the operation authority of the data on the chain.Secondly,the data storage method of on-chain and off-chain collaborative storage is proposed: by deploying the IPFS distributed data storage system under the consortium chain,the source files are stored in the IPFS system,and the system returns the file hash digest generated based on the file content.By calling smart contracts to send transactions and store them on the alliance chain,the data storage pressure on the alliance chain can be shared to the maximum extent.(2)The data hash digest is encrypted by a certificateless cryptographic system,so that the data that is not protected on the chain still has a permission control mechanism and restricts the user's access to the data.In order to further protect the security and privacy of off-chain data,this paper proposes to use a certificateless cryptosystem to encrypt and decrypt file hash digests.Users can use the certificateless cryptosystem to generate a pair of public and private keys based on their identities,and encrypt the data with the public key of the user with data access rights.Only the private key of the user can decrypt the data,so as to realize the use rights of off-chain data further control.(3)Design a relay-based cross-chain system to complete cross-chain asset transfer and cross-chain information query operations between blockchains.This paper designs a relay-based cross-chain communication system.A distributed execution protocol for cross-chain communication scenarios is proposed to ensure the atomicity of cross-chain interactions when cross-chain steps are cumbersome or when multiple chains cross-chain at the same time.The block header synchronization contract for cross-chain transaction verification is designed,which simplifies the cross-chain transaction verification process and improves the cross-chain transaction verification efficiency.It realizes data sharing and related business collaboration between different blockchains.This paper uses the IPFS-based blockchain data trusted storage system to achieve secure and trusted storage of data,effectively preventing data from being abused,tampered with or destroyed.Secondly,this paper improves the relay-based cross-chain communication mode,and proposes a relay-based consortium chain cross-chain communication system,which improves the performance and versatility of blockchain cross-chain communication and increases the efficiency of cross-chain communication.Security and reliability,it can complete the cross-chain communication function of inter-chain asset transfer and information sharing.