With the huge development in the field of data storing and processing as well as the impending development of the internet, accessing information and resources is becoming faster, cheaper and more available. This has paved the way for a new development in the world of computing, networks and operating systems, which is “Cloud Computing”. In this project, we present a solution for the problem of secure data sharing in a safe and dynamic way on Public Cloud. The process is done without re-encrypting the shared data or re-distributing keys as the case in most solutions so far. Also, include a step towards the completion of access control UCON, where we studied the ability for a user to delegate another user OWNER role and sharing data authorization.