Dynamic Policy Update on Cloud for File Access

In today’s era of digitalization everyone stores and access data online. Cloud computing has become prominent in data storage and access any where globally, but there is concern by data owners regarding data ownership. It is monotonous to assign access rights and simultaneously provide security in real time is a concern. To resolve this issue of access control in recent times Attribute based encryption method is widely preferred. One of the most popular method to handle access rights is by used is Attribute-based Encryption (ABE) method, the two ways for performing the implementation of ABE are ciphertext-policy and key-policy ABE. One of the widely practiced methods of safe communication is through cryptography. In this work we are proposing a method to handle access rights dynamically on the outlines of Ciphertext-policy attribute-based encryption (CP-ABE) scheme along with this we are using two symmetric encryption algorithm namely AES and Serpent for providing better security to the system. This work implements a new policy update method which helps to manage data access control in the dynamic policy update for data in the cloud storage. In this, same input key is utilized for the both encryption and decryption operation. Here two types of files are handled as an input such as Text file and image file. In experimental result, comparison of both algorithms is shown with the help of graphs with different parameters such as Time, Number of files, file size. And we have also shown the comparison of system having dynamic update policy and system with out in tabular form. We have also shown the comparative analysis of both algorithms that shows SERPENT encryption algorithm gives superior performance in Encryption