Blockchain based Encryption Method Cloud Security using Third Party Auditing

The invention of cloud storage (CS) has brought great convenience in its application to the day-to-day lives of people. An enormous amount of data is rendered via a third-party server (TPS) by several enterprises or individuals for CS, and such usage creates the need to preserve the privacy of Cloud User's (CU) data with guaranteed security needs. While retrieving the data requested, the CU's information has to be ensured for authentication and needs to be processed by faster searchable encryption methods for the CS environment. Several schemes provide a search based only on the keywords and do not support the updating of files in them, because of which the flexibility of the CS model is reduced. This research proposes a blockchain based public key encryption scheme by utilizing a search mechanism based on multiple keywords that also complies with the updates on the files. Moreover, t ransaction fairness is verified between the Data Owner (DO) and the CU without any third-party involvement via a smart contract of the proposed Blockchain based encryption (BCE). The CU accesses the data requested, completely after ensuring that the Cipher Text (CT) is received and the files are numbered for verifiability at the CS stage itself. The introduced BCE method outperforms the existing method with a more secure and computationally efficient CS model in terms of security and performance. The experimental results demonstrate that the proposed method consumes lesser time in decryption and encryption of 240ms and 1320ms, respectively for a data size of 1000 bits. On the contrary, the existing method consumes 2210ms for encryption and 250ms for decryption.