Abstract: - - In recent times, with the emergenceof cloud technologies and exponential growth of cloud storage systems, manycloud-based services have evolved and public cloud storage is gainingprominence due to the availability of cloud storage at much cheaper prices whencompared to private cloud systems. However as cloud storage is public, there isa risk of privacy loss and other security concerns. In general, the publiccloud storage systems give subcontracts to semi-trusted cloud servers for thestorage of data. These cloud servers do not fall into the scope of trust of thedata owners and there is a risk that the service providers might get access tothe data owners' sensitive data. The main challenge in this project is how toregulate the access of cloud servers over the. data owner’s sensitive data. In general, the data that is stored on suchpublic cloud storage systems is encrypted using cryptographic techniques toprevent unauthorized usage. A sophisticated trait supported encryption hasemerged as a novel technique that can enforce access policy restrictions overthe data traits. But existing trait-based techniques give no support forcollaboration. In this project, we try to discover and come up with a newtrade-based cryptographic technique that can help Multiple users with multiplesets of trade data to collaborate and access the data owners' data. Also, wetried to implement a collusive detection scheme that identifies anycollaboration that is not part of the access policy ask allusion orunauthorized access, and such access requests would be denied. When multipleuser groups collaborate to ensure data there is a high chance that there wouldbe duplicate documents in the same environment hence we proposed a techniquefor the deduplication of content present on the cloud nearby reducing the costsincurred due to duplicate data. Security analysis and performance analysis ofthe recommended technique show that the proposed system fetches good resultsand it is implementable in real-time environments.
Keywords: - Public cloud storage, Access control, CP-ABE, Collaboration