Searchable Encryption Scheme Based On Fuzzy Keyword In Cloud Computing

In this age of internet, higher requirement of storage makes the data outsourcing being an inevitable trend of network development in the future. With the cloud computing being mature, most users tend to store the data on the cloud server. But cloud server may not be completely trusted, data usually have to be encrypted before outsourcing for protecting the data privacy, which makes searching over ciphertext become a challenging task. Searchable encryption schemes are presented to solve this problem. However, traditional searchable encryption schemes, which are no tolerance of minor typos and format inconsistencies, only support exact keyword search. This significant drawback makes exact keyword search unsuitable in cloud computing. To solve this problem, fuzzy keyword search over encrypted cloud data is proposed. This scheme greatly enhances system usability by returning the matching files when users’ searching inputs exactly match the predefined keywords or the closest possible matching files based on keyword similarity semantics, when exact match fails.Based on the existing fuzzy keyword search techniques, this paper proposes an efficient fuzzy keyword searchable encryption scheme, the main work includes as follows:1. This paper first introduces the symmetric and asymmetric searchable encryption schemes, which are not support fuzzy keyword search, so the fuzzy searchable encryption scheme is mainly analyzed then.2. Compared with "Wildcard-based Fuzzy Set Construction" method in traditional theme, this paper presents a "Word-based Fuzzy Set Construction" method. The elements in this construction are meaningful and the size of that is reduced. With a symbol-based search tree, the method in our scheme makes the whole scheme reduce memory apace and search time.3. In the traditional scheme, it is not feasible for us to take the results from public cloud as current search result directly. This paper proposes an effective verification algorithm to verify the search result returned by public cloud, which makes the whole system more reliability.4. This paper puts forward a more sound system model, data owners and users don’t need to bear the heavy computational tasks which are transferred to private cloud. This enhances the service level of outsourcing system.5. Based on single keyword search, this paper proposes a fuzzy multi-keyword search algorithm, which can satisfy the higher requirements of users for retrieving interested files. In this theme, users can submit the combination of multiple keywords. Both the precise of search results and search function are improved.