PRESERVING PRIVACY ACCESS CONTROL WITH FLEXIBLE DATADISTRIBUTION FOR DYNAMIC GROUPS IN CLOUD

Cloud computing is increasing computing a model that allows customers to keep the data in a cloud to enjoy with data availability and facility services. But, it also causes a lot of safety problems to recognize cloud provider providers (CSP). As per the records, the cloud server is un-trusted to against the CSP and present applications providing cryptographic mechanisms (Encryption and decryptions methods) and the availability of much powerful decryption keys for authorized clients. One of the primary cryptographic encryption mechanisms is identity-based encryption (IBE) is used to create authorized data sharing in the cloud. But control the access policy is no longer made. That means, when some user's access permission has expired, there necessary a mechanism that can revoke a particular user from the server. Therefore, the removed user cannot access the before shared data and after shared data also. Various researchers provided many algorithms to provide security in dynamic group data sharing. For example, the encryption mechanism is attribute-based encryption (ABE) and cipher text policy-based attribute-based encryption (CP-ABE). But there is a still challenge in their works. To solve the problems in previous works this paper proposed an effective modified revocable attribute-based encryption (MRABE) with the excellence of ciphertext allocation by providing both Identity Based Encryption (IBE) and Ciphertext policy attribute-based encryption schemes (CP-ABE). It can present forward / back confidentiality of the encrypted information by providing consumer attributes revocation and updating the encrypted content at the same time. Further, we implement one of the access control mechanism is fine-grained access control mechanism and sharing cloud facility services with dynamic cloud user groups. The Empirical results show that the proposed mechanism is more effective and scalable than the previous mechanisms.