Abstract: Cloud computing has been envisioned as the next generation computing which enable the users to shareon-demand resources over the internet for cost effective IT services.While outsourcing the data using cloud storage several security issues arises such as confidentiality, integrity and authentication. Each of them plays an important role in the successful achievement of the other. Specifically no security strategy is achieved without assuring data integrity. In cloud computing data integrity assurance is one of the major challenges because the user has no control over the security mechanism that is used to protect the data. Data security refers to the protection of data against unauthorized access, modification or corruption and also it is necessary to ensure data integrity. Data integrityinsures that data receivedis same as data stored.It is a result of data security but the term data integrity refers to the validity and accuracy of data rather than protect the data.It is an important aspect of storage security and reliability of data. In this study, a new technique using the diagonal based rotational technique is used to enhance the performance of both data integrity violation checking in terms of storage bit reduction and time consuming and security of cloud storage. In particular, avoiding the burden of Third Party Auditor (TPA) is considered. The new model provides a mechanism to enhance data security through improving the performance of detection of data integrity violations as well as hiding the information from unauthorized users. In this approach, the data is partitioned into number of blocks and then converted into a square matrix. Determinant factor of each matrix is generated dynamically to ensure data integrity. This model also implements a combination of SHA-256 algorithm for message digest generation and Two fish algorithm for encryption are known as digital signature. Data coloring on digital signature is applied to enhance data security. This combination provides an efficient mechanism as three ways checking to enhance data integrity and data security between the client and the cloud provider. Also block level implementation of the proposed method makes computation faster. The proposed method utilizes attributes such as encryption time and decryption time, memory utilization and execution time to improve the efficiency for verification of untrusted and outsourced storage. The performance analysis using cloud simulator shows that the proposed scheme is highly efficient and secure as it overcomes the limitations of previous approaches of data security using encryption and decryption algorithms and data integrity assurance methods using TPA. Thus, the proposed scheme reduces the server computation time, memory utilization and also achieves maximum level of accuracy while compared with the previous.
P. Premkumar and D. Shanthi, 2016. Enhancing Data Security Through Block Level Data Integrity Assurance using Diagonal Based Rotational Technique on Cloud Storage. Asian Journal of Information Technology, 15: 4916-4925.