A Secure Architecture for Access Control with Hashing Technique in Public Cloud

Traditional approaches are inefficient to support finegrained encryption. Under such approaches, data owner is responsible for encrypting the data before uploading them into cloud and re-encrypting the data whenever there is a change in user’s sub access control policy. Data owners thus incur high communication and computation costs. In order to minimize the overhead at the data owner, fine-grained access control has to be delegated to the cloud. The cloud performs a fine-grained encryption and the data owner performs coarse-grained encryption. Cloud encrypts the data that is already encrypted by the data owner. Efficient cryptographic algorithms such as Residual Number System (RNS) and Elliptical Curve Cryptography (ECC) are implemented. Both RNS and ECC reduce the computational cost. Integrity check is also been used. Thus the proposed system preserves user’s privacy and ensures data confidentiality. Keywords— Cloud Computing, Encryption, Fine-grained access control, Hashing, Privacy.