Data retrieval based on the smart contract within the blockchain

Abstract

Blockchain technology appears to be the ideal solution for storing data in a transparent and decentralized manner. It also allows open access to data and enhances its immutable nature. This technology has helped prove its usefulness in several industries so far, however, distributed ledger technology does not work as a pure database. Therefore, some problems occur in accessing data. Querying data in the blockchain leads to performance and bandwidth problems. This primarily occurs because the blockchain does not have a primary query language, unlike regular databases. The distributed nature of the blockchain is in this case an obstacle. In this paper, a safe and fast method will be proposed to retrieve consistent data from the blockchain-based on the smart contract that will be opened after completing the transaction procedures. All nodes will sign the proposed transaction (by adding a special hash to each node resulting from the transaction information and node data). Upon completion of Transaction procedures, A smart contract will be opened (in which a QR is placed) resulting from converting the signatures in the transaction to QR When the smart contract data is retrieved, the QR for each transaction will be used All node signatures and transaction data will be extracted. The data will be retrieved by the QR generated for each transaction after it is stored in all nodes servers participating in the system. A new method was proposed to generate a hash for each node present in the system. The proposed method was tested in terms of time and complexity, and the algorithm was statistically analyzed, and all the results proved successful.