Abstract
One of the biggest challenges for cloud users is to prevent data breaches or malicious attacks on their data on the cloud. Cloud data breaches occur when unauthorized users or cloud service providers (CSPs) try to access sensitive information of the cloud users. Despite CSP’s data encryption techniques in transit and at rest to protect data from unauthorized users, a user’s cloud data has a potential threat from CSPs as they may learn the user’s plaintext data. Hence, a secure cloud environment is essential for data submission, storage, and destruction. In this project, a secure data sharing application is proposed to fulfill the major security requirements for data storage on the cloud using Homomorphic Encryption (HE) and Advanced Encryption Standard (AES) with Diffie-Hellman (DH) key exchanges. The data is encrypted with HE before uploading to the cloud; hence the data will be in encrypted form on the cloud to avoid data breaches at rest by the CSPs and third-party users. The data files can be shared among multiple users within the application using AES encryption with a secret key generated by a DH key exchange. A Lease-Based (LB) mechanism is implemented for the secure destruction of shared data files. This mechanism deletes the shared file on the cloud and on the local device of the shared user once the lease-limit is met.