Biblio

The main searching functions realized by searchable encryption can be divided into searching using one query and searching using multiple queries. Searchable encryption using one query has been widely studied and researched; however, few methods of searchable encryption can accommodate search using multiple queries. In addition, most of the method proposed thus far utilize the concept of index search. Therefore, a new problem exists, in which an additional process of updating or deleting an index when new documents are added or removed is required. Hence, the overall computation cost increases. Another problem is that a document that is not registered in the index cannot be searched. Therefore, herein, using a secret-sharing scheme that is known to offer a low computational cost, we propose a method that can realize both logical conjunctive (AND) and logical disjunctive (OR) search over multiple conditions, without the construction of any index. Hence, we can realize direct searching over sentences, thus achieving a more efficient search method.