Reducing extra storage in searchable symmetric encryption scheme

In order to protect the data privacy, cloud users usually outsource the encrypted form of their data to the cloud servers, which brings a challenge when they want to search their encrypted data in cloud. Searchable encryption techniques solve this problem by allowing the cloud servers to search on the encrypted data without decrypting the ciphertext or the searching keywords. In this paper, we propose a construction which can dramatically reduce the size of extra storage in the searchable symmetric encryption schemes and still remain efficiency. And security analysis shows that our construction can achieve non-adaptive secure. Further investigation and experiments show that our construction is suitable for not only single keyword search but also more complex search including conjunctive search, disjunctive search and phrase search.