| In recent years,digital expression of assets has become a necessary way.However,due to the fact that digital objects are easy to be copied and have no natural rights confirmation mechanism,traditional asset digitization technologies bring a series of risks.Specifically,the security risks and maintenance costs of existing digital asset storage solutions are high.Blockchain,based on a distributed ledger,can ensure that data stored in blocks is tamperresistant,but its storage scalability is limited.In addition,current digital asset sharing often ignores the issue of over-disclosure.A common principle proposed by many privacy protection regulations is data minimization,which means choosing the minimum amount of data to share while hiding other unnecessary parts and providing evidence to prove the authenticity of what is disclosed.However,for a complete digital asset,its authenticity is easy to verify,but when only a portion of the data is extracted for sharing,it is difficult to verify without exposing the complete asset content.In this paper,we first focus on the secure storage of digital assets,based on which the sharing of assets is divided into selective disclosure of individual assets and minimal sharing of batch assets,and the verification mechanism of sharing process is further investigated respectively.The main contributions of this paper are as follows:1.The asset minimization sharing model based on on-chain and off-chain storage is proposed.In the off-chain P2P storage network,the original data is encoded by the Erasure Coding and generate redundant data,which provides high data reliability and availability while greatly reducing the system storage consumption and realizing fault-tolerant storage of digital assets.The digest information of digital assets is recorded on the blockchain,the decentralized environment ensures the verification of the original digital assets on off-chain.Meantime,the storage model supports minimal sharing by chunking pairs of assets.2.The mechanism for selective disclosure and verification of individual assets is proposed,which designs a low-maintenance authenticated data structure based on the chunked storage of Erasure Coding,in which,users can choose to disclose any part of the data,while providing trusted proofs for the disclosed data.The proof data consist of redundant information and irrelevant hash values obtained,and the undisclosed data is completely invisible,which satisfies high privacy protection and security requirements while reducing the responsibility of handling unnecessary data.3.Minimal sharing and verification mechanism for batch assets is proposed.To achieve efficient validation of shared content,the mechanism aggregates the hash of attributes in the batch assets and generates the aggregated digest,which extends the validation of individual assets to types of assets.Further,based on the accumulator,multiple types of assets within the block are aggregated,and the authenticated data structure is designed in the block,which can generate trusted proofs for the shared data and supports dynamic aggregation of any query attributes,enabling efficient shared and verification. |
