Cloud computing (CC) is one of the most prominent storage and computing platforms being researched nowadays. CC platforms are providing the opportunity for sharing resources, information, and services among the users of the entire world. For data storage and processing, cloud security considerations are critical. Because data in a cloud based environment must be protected from hackers, network security has been a key concern in recent years. Data should be encrypted and outsourced to the cloud to safeguard it from malicious intruders. Cryptography is essential for protecting data from various assaults and cloud storage platforms. To overcome the security threat new types of cryptography techniques can be introduced. Though a variety of firewall systems exist, there are still threats or attacks on the data or information which is transmitted over the cloud. The invention focuses on addressing the flaws that are inherent in network security by using advanced encryption techniques to encrypt data over the cloud. In this research work, a blockchain (BC) based user authentication system and improvised public-key cryptosystem are proposed which is based on Rivest-Shamir-Adleman (RSA) to support a private key cryptosystem. The proposed work comes under the following phases: user registration, login, authentication, BC, sensitive data identification, data splitting, and data security. Finally, the performance of the proposed framework in comparison with existing techniques determines strong results and proves to be more secure.

A cloud environment is a collection of resources used to provide on-demand services to cloud clients. Access to the cloud environment is supplied through internet services, and data kept in the cloud environment is more accessible to both internal and external invaders. At the moment, cloud security experts are unable to provide a more dependable, safe, and effective intrusion detection system (IDS) for identifying intruders in data transfer. For fulfilling this requirement, in this paper a novel deep learning (DL) model namely Wavelet Kernel including Multi-Layer Perceptron Neural Network (WKMLPNN) based IDS is proposed for identifying the attacks while performing cloud data transmission. Additionally, to offer cloud secure storage, Improved Elliptical Curve Cryptography (IECC) is proposed with a novel key generation mechanism. Initially, the cloud user or data owner (DO) is registered with the Cloud Service Provider (CSP) for uploading their data to the cloud. Then at the CSP end, the authenticity of the DO is checked by implementing the Secure Hash Algorithm 256 (SHA-256) technique. After successful authentication, the DO is allowed to upload their data to the cloud. The CSP receives the data from the DO and then the intrusion present in the received data is identified using novel IDS (WKMLPNN). The presented IDS follows three operations such as preprocessing, optimal feature selection using Time factor incorporated Gravitational Search Algorithm (TGSA) and WKMLPNN applied classification for identifying the intrusions present in the data. If the received data contain the intrusion, the data will be avoided and not stored in the cloud, otherwise, the data will be stored in the cloud securely using the IECC algorithm. Finally, if the cloud users request CSP for data retrieval, the authenticity of the user is again checked using the SHA-256 algorithm. If the user is an authenticated one, the retrieval permission is granted for him, otherwise, the permission is denied for the user. The simulation results reveal that the presented approach outperforms existing strategies for intrusion categorization and encryption.