Multi-Cloud Based Data Backup Services for Android Device

Abstract

Keyword search under the multi-tenancy setting is a more common scenario. In such a scenario, the data owner would like to share a document with a group of authorized users, and each user who has the access right can provide a trapdoor to perform the keyword search over the shared document, namely, the “multi-user searchable encryption” (MUSE) scenario. Some recent work focus to such a MUSE scenario, although they all adopt single-key combined with access control to achieve the goal. In, MUSE schemes are constructed by sharing the documents searchable encryption key with all users who can access it, and broadcast encryption is used to achieve coarse-grained access control. attribute based encryption (ABE) is applied to achieve fine-grained access control aware keyword search. As a result, in MUSE, the main problem is how to control which users can access which documents, whereas how to reduce the number of shared keys and trapdoors is not considered. Key aggregate searchable encryption can provide the solution for the latter, and it can make MUSE more efficient and practical. The aim of proposed work is to design an Extended Cryptographic Mechanism for Secured Data Sharing in Cloud using Multiple Keys. Data sharing is an important functionality in cloud storage. In this project, we show how to securely, efficiently, and flexibly share data with others in cloud storage. We describe new public-key crypto-systems that produce cipher texts such that efficient delegation of decryption rights for any set of cipher texts is possible.