Design And Implementation Of Digital Asset Deposit Certificate System Based On Blockchain

As the real economy gradually transforms into a digital economy,a large number of digital assets created by individuals or enterprises begin to circulate in the network,which facilitates data sharing and also has many difficult problems.Security incidents such as user privacy disclosure,copyright disputes,data theft,etc.occur frequently,seriously harassing people's normal work and life.In addition,digital assets are naturally characterized by volatility and vulnerability.Once a single point of failure or virus infection occurs,it is likely to destroy its original state,thus losing its value.Moreover,the general user's awareness of evidence collection,deposit verification,and attestation is weak,leaving the criminals with an opportunity.However,the common deposit certificate has the defects of fewer depository institutions,weak anti-tampering ability,and low evidence validity.It is necessary to replace it with a new depository technology.After in-depth analysis and research on the characteristics of digital assets,this paper designs and implements a digital asset depositing system based on blockchain.The system utilizes blockchain decentralization,trust-free,secure and transparent,tamper-proof,collective maintenance and traceability,combined with distributed data storage,P2 P communication,smart contract,consensus mechanism,cryptography,Token incentives and other technical means.Digital assets such as pictures,audio and video,e-mail,and electronic contracts are fixed in the form of hash fingerprints.In addition,the IPFS system implements fragmentation and hashing of digital assets to compensate for the natural storage defects of the blockchain;the Merkle tree guarantees the integrity and validity of the transaction data;the timestamp technology and the chain structure do Backtracking historical data.Smart contracts are responsible for automating business logic and program code to reduce the impact of human factors;asymmetric encryption for encryption and authorization;and PoA consensus algorithm for verifying transaction and block generation to maintain stable operation of the entire blockchain network.After experimental verification,the system can realize the function requirements of file encryption,file uploading,file fragmentation,file downloading,file viewing,evidence fixation,file authorization,file comparison,etc.In the process of completing the above work,the smart contract is also carried out.Write,compile,deploy,and call.The certificate user can interact with the Kovan test network through the JSON-RPC API encapsulated in the Web3.js on the web front end.After completing the above operations,the judicial authenticationauthority can be authorized to obtain the certificate data on the blockchain,and the original document is used.Compare the corresponding judicial appraisal report.This paper provides a good reference for the deposit and preservation of corporate or personal digital assets.