Verifiable Query Framework Of Blockchain Based On Cryptography Accumulator

With the rapid development and application of blockchain technology,more and more scenarios are developed and applied with the support of blockchain technology,which makes blockchain technology no longer limited to cryptocurrency,but more widely used in all scenes in life that need its technical characteristics.With the wide application of blockchain technology,there is a growing demand for query,which has higher requirements for the query performance and security of blockchain database.Blockchain has open query rights to anyone.For ordinary users,only light nodes with small amount of data need to be downloaded to query data,and the merkleroot of block head can verify whether the data is tampered with.This method can meet the user's needs to some extent,but the shortage is that the query method of light node cannot verify the integrity of the query results,so there is a risk of cheating due to incomplete query data in some scenarios,such as the service provider of blockchain database may reduce the query results due to commercial interests and other reasons.In order to avoid the risk of blockchain database query,users can use the whole node query method,that is,maintain the whole blockchain database and query data locally.But the disadvantages of this method are obvious.Because of the continuous growth of blockchain,it is necessary to maintain the huge amount of data of the whole node,which is not feasible for general users,especially mobile users.In view of the integrity verification of blockchain database query,a block chain database verification query framework is proposed.The purpose of this framework is to ensure the integrity of query results and reduce the storage and calculation cost of query users.In order to support verifiable query,a authentication data structure based on cryptography accumulator is proposed,and the structure is extended to blockchain structure to realize dynamic aggregation of attribute sets.In addition,the aggregation ability of verifiable data structure is extended to the range query of numerical properties.At the same time,in view of the performance challenges brought by integrity verification,two new data structures,MB accumulation tree and jump tree,are proposed to index and aggregate data records within and between blocks to achieve more efficient query and batch verification.In conclusion,the whole block chain database verifiable query framework extends the block structure and adds index structure,which can guarantee the integrity of query results,and provide the user with integrity Certificate in the form of zero knowledge proof to solve the above problems.