Secure Data Authentication for Remotely Stored Data Using Bilinear Pairing on Elliptic Curves With Optimized Data Block Size

As cloud computing grows exponentially, businesses depend increasingly on distant servers to store enormous volumes of data. However, it is not easy to guarantee the confidentiality and integrity of data stored remotely. Unauthorized changes, whether intentional or unintentional, might jeopardize data accuracy, underscoring the pressing need for strong data authentication procedures. Currently, data is stored in the cloud to save money on storage. It is essential to check if any changes to the data were done intentionally or by mistake. This presents a key challenge: ensuring that remotely stored data remains intact and unmodified by users. Hence, in this system, it is proposed that the authenticity of data possession be verified and its integrity audited. Our proposed system for cloud data authentication aims to be audited by an authentic user/auditor to confirm any changes made in the original data once it is placed on remote storage. The proposed system considers essential factors such as response time, data storage space requirement and preservation of strong Security for the client's data. To achieve design and implementation, modern cryptosystems, such as Elliptical Curve Cryptography (ECC) with Bilinear Pairing (BP), possess a strong mathematical foundation. The homomorphism property of bilinear pairing is used as it allows performing operations on ciphertext to verify the integrity of uploaded data by the auditor without compromising confidentiality. Furthermore, optimization of data block size is introduced in our system, which encourages the practical use of asymmetric key cryptosystems for applications handling large volumes of data. Our ECC with Bilinear Pairing-based approach is also helpful for dynamic data verification in a cloud storage environment. Experimental results show that for a 1 MB file, encryption and decryption times using the suggested BPECC technique were approximately 24 min 51 s and 10 min 20 s, respectively, significantly outperforming RSA and Boneh-Goh-Nissim (BGN), which required up to 2 h 59 min for decryption. Moreover, storage overhead remains low due to efficient tag generation and block size optimization. Experimental results demonstrate that our system outperforms other homomorphic encryption schemes like BGN, RSA, ElGamal, and Paillier regarding encryption/decryption speed and storage overhead. This makes it a suitable solution for practical cloud storage applications.