Efficient and non-interactive ciphertext range query based on differential privacy

Differentially private range query schemes satisfy differential privacy by adding or deleting records during the process of creating index which suffers from the weakness of data loss in query results due to the negative noise. Recently, Sahin et al. (2018) proposed a differentially private index with overflow arrays in ICDE 2018, which ensures the integrity of query results. However, this scheme suffers from two drawbacks: 1) some private information (e.g., query requests or frequency) may be leaked because of querying over plaintext index; 2) the overflow arrays bring extra storage overhead. To this end, we present a non-interactive ciphertext range query based on differential privacy and comparable encryption. Our scheme can protect the query privacy since the query is performed over ciphertext based on comparable encryption. Besides, the experiment results show that our proposed scheme can save the storage overhead.