DRSMS: Domain and Range Specific Multi-Keyword Search over Encrypted Cloud Data

One of the most fundamental services of cloud computing is Cloud storage service. Huge amount of sensitive data is stored in the cloud for easy remote access and to reduce the cost of storage. It is necessary to encrypt the sensitive data before uploading to the cloud server in order to maintain privacy and security. All traditional searchable symmetric encryption (SSE) schemes enable the users to search on the entire index file. In this paper, we propose the Domain and Range Specific Multikeyword Search (DRSMS) scheme that minimizes the search time and Index storage space. This scheme adopts collection sort technique to split the index file into D Domains and R Ranges. The Domain is based on the length of the keyword; the Range splits within the domain based on the first letter of the keyword. A mathematical model is used to search over the encrypted indexed keyword that eliminates the information leakage. Binary search is used to select the range within the domain with time complexity O(RlogD) and linear search is used to find the keyword within the range with O(R). The space complexity of the index storage space is O(NT × 3) and search time complexity is O(1)+O(RlogD)+O(R), while the complexity of index generation is O(NT × 3). Extensive experiments on real-world dataset validate our analysis and shows that the proposed DRSMS scheme is more efficient and secure than RSSE Scheme.