Query Communication Cost Research Articles

Facilitating Secure and Efficient Spatial Query Processing on the Cloud

Database outsourcing is a common cloud computing paradigm that allows data owners to take advantage of its on-demand storage and computational resources. The main challenge is maintaining data confidentiality with respect to untrusted parties i.e., cloud service provider, as well as providing relevant query results in real-time to authenticated users. Existing approaches either compromise confidentiality of the data or suffer from high communication cost between the server and the user. To overcome this problem, we propose a dual transformation and encryption scheme for spatial data, where encrypted queries are executed entirely at the service provider on the encrypted database and encrypted results are returned to the user. The user issues encrypted spatial range queries to the service provider and then uses the encryption key to decrypt the query response returned. This allows a balance between the security of data and efficient query response as the queries are processed on encrypted data at the cloud server. Moreover, we compare with existing approaches on large datasets and show that this approach reduces the average query communication cost between the authorized user and service provider, as only a single round of communication is required by the proposed approach.

Secure MAX/MIN Queries in Two-Tiered Wireless Sensor Networks

In wireless sensor networks, secure MAX/MIN query processing is a challenging issue, and it is useful in fields, where security is necessary. In this paper, we propose a secure MAX/MIN query processing method in two-tiered wireless sensor networks. To the best of our knowledge, it is the first work that can achieve data privacy protection and query result integrity verification simultaneously. Three schemes, naive secure MAX/MIN query (NSMQ), complicated secure MAX/MIN query (CSMQ), and OSMQ, are designed to achieve secure MAX/MIN queries. In NSMQ, we present an intuitive and baseline solution that makes the master nodes return all the ciphertext as the query result. However, it may incur high query communication cost. To address this limitation, a CSMQ scheme is designed, which introduces the comparable factors (c-factors) based on 0–1 encoding verification to find the accurate encrypted query result from the stored ciphertext of the master nodes even when their real values are unknown. Then, a broadcasting method is introduced to generate minor-node-sets as the proofs for verifying the integrity of the query results. CSMQ can significantly reduce the query communication cost, but its in-cell communication cost is high because of the extra data submission and broadcasting. To balance the in-cell and query communication cost, OSMQ, as an optimized version of CSMQ, is proposed to address the minor-node-set compression and random c-factor selection. The proposed schemes are built upon symmetric encryption and hash-based message authentication coding primitives. OSMQ can prevent compromised master nodes from obtaining the plaintext of private data and force them to return integrity-satisfying query results to avoid being detected. Extensive theoretical and experimental studies have been conducted to demonstrate the efficacy and efficiency of the proposed schemes.