Achieving Efficiency of Encrypted Cloud Data with Synonym Based Search and Multi-Keyword Ranked Search

Nowadays, cloud computing becomes efficient and flexible with reduced cost and utility of on-demand high quality applications and services, so internet usage strongly relies on cloud for privacy preserving and fast data retrieval. For consumers, they want to find the most relevant products or data, which is highly desirable in the ?pay-as-you use? cloud computing paradigm. Sensitive data (such as photos, mails, health records, financial records, etc) is encrypted before outsourced to cloud. Although Searchable encryption scheme has been developed to conduct retrieval over encrypted data, these schemes only support exact or fuzzy search, mainly evaluate the similarity of s from the structure but the semantic relatedness is not considered. This work focuses on realizing secure semantic search through query semantic extension based on the co-occurrence probability of terms, the semantic relationship library is constructed to record the semantic similarity between s. To achieve efficiency of the search method we enhance the TFIDF algorithm by extending the set with semantic words or natural language words for the s. This will ultimately support data retrieval on querying semantic query. Even when user doesn't know exact or synonym of s of encrypted data, he can try searching it by its meaning in natural language. WordNet method makes the search scheme even more reliable and better.