Privacy Preserving Secure Query Processing For Database-as-a-Service

Network technology developed continuously.Database-as-a-Service has been proposed and received extensive attention.As a consequence,data privacy preserving has become the most important problem during this Database-as-a-Service time.In Wireless Body Area Network(WBAN),it has been proposed a secure privacy preserving kNN query protocol,which employs the ASPE to encrypt both data and queries.On the basis of combine the technologies of R-tree and bucket partition,a data structure named BRtree for indexing data items is proposed to improve searching efficiency.BRtree can significantly eliminate the unnecessary searching branches.In order to achieve access control,we separate an access key from the encryption key and introduce a trusted third authority to manage access rights and access rights transferring.The experimental results validate the efficiency of the proposed scheme.In two-tiered sensor networks,privacy and integrity has been the main road block to the applications.The storage nodes,acting as a middle tier between sensors and the sink,could be compromised and allow attackers to learn sensitive data and manipulate query results.We propose the first top-k query processing scheme that protects the privacy of sensor data and the integrity of query results.To preserve privacy,we build an index for each sensor to collecte data item using pseudo-random hash function and Bloom filters,which transforms top-k queries into top-range queries.To preserve integrity,we propose a data partition algorithm to partition each data item into an interval and attach the partition information with the data.The attached information ensures that the sink can verify the integrity of query results.It is formally proved that the proposed scheme is secure under IND-CKA security model.The experimental results on real-life data show that this approach is accurate and practical for large network sizes.In conclusion,we proposed a privacy preserving secure kNN query protocol in wireless body area network,which implemented privacy preserving secure query processing and access control.We also proposed a privacy preserving and integrity authentication Top-k query protocol in two tiered sensor network,which implemented privacy preserving secure query processing and integrity authentication of query result effciently.