PRIVACY-PRESERVING MULTI-KEYWORD TOP-K SIMILARITY SEARCH OVER ENCRYPTED DATA

Identity-based encryption is used to build data sharing system. In order, access control is not static. It means that when authorization of some users is expired, the system should remove his (or) him. By that the removed user cannot access both forward and backward data. For this we use a concept called revocable-storage identity-based encryption (RS-IBE), which provide security of cipher text for forward/backward data by introducing the user revocation functionalities and simultaneous update of cipher text. We provide a detailed structure of RS-IBE, which certifies its secrecy in the described security model. The realistic and cost-effective system of data sharing is achieved by this RS-IBE scheme which has tremendous benefits of operability and capability. Certainly, we provide implementation outcome of this suggested scheme to define its feasibility. In this paper, we address this practical problem, which is largely neglected in the literature, by proposing the novel concept of key aggregate searchable encryption (KASE) and instantiating the concept through a concrete KASE scheme, in which a data owner only needs to distribute a single key to a user for sharing a large number of documents, and the user only needs to submit a single trapdoor to the cloud for querying the shared documents. The security analysis and performance evaluation both confirm that our proposed schemes are provably secure and practically efficient. This approach acquaints the utilities of user repudiation and cipher text update concurrently. Additionally, we provide a detailed structure of Searchable-IBE, which certifies its secrecy in the described security model. The realistic and cost-effective system of data sharing is achieved by this Searchable-IBE scheme which has tremendous benefits of operability and capability. Certainly, we provide implementation outcome of this suggested scheme to determine its feasibility.