Secured Data Sharing in Cloud Environment Using Proxy Re-Encryption Techniques

This project implements a Proxy Re-Encryption (PRE) system for secure data sharing and management in a cloud-based environment. The core objective is to enable a cloud owner to securely upload data, divide it into multiple parts, and allow a data user to access and modify this data while maintaining confidentiality and integrity. Initially, the cloud owner uploads a file, which is split into four segments. Each segment undergoes a hashing process using the SHA algorithm, generating four distinct SHA hash values, which serve as integrity verifiers for the respective parts of the data. To protect data during the sharing process, the owner encrypts the data before granting access to a specific data user. The encrypted file is then subjected to proxy re-encryption, where a proxy server, without learning anything about the contents of the file, re-encrypts it on behalf of the owner. This allows the data user to decrypt the file securely with the provided key. The cloud server manages this process by performing the re-encryption and sharing the encrypted file and key with the user. In this system, only authorized users with the necessary permissions, granted by the cloud owner, can access the file content. The use of proxy re-encryption ensures that the cloud server does not need to have direct access to the unencrypted data, preserving data privacy and security. This project enhances secure data sharing and access in cloud environments, offering a high level of data confidentiality, integrity, and control for the owner while enabling safe and selective access for users