PCTopk: Privacy- and correctness-preserving functional top-k query on un-trusted data storage in two-tiered sensor networks

This paper proposes an efficient mechanism, called PCTopk, for functional top-k query with a combination of multiple conditions/dimensions in two-tiered sensor networks to simultaneously preserve data privacy and correctness (i.e., authenticity and integrity). PCTopk constructs a layered authentication tree, cooperated with an order-preserving symmetric encryption technique, for only permitting storage nodes to systematically process inquired data over encryption domain and enabling querists to efficiently verify the authentic and complete query results. To the best of our knowledge, this is the first research work on the issue of secure functional top-k query with a combination of multiple conditions in two-tiered sensor networks. The performance evaluation results show that PCTopk takes significantly less energy consumption and storage space than prior arts while preserving data privacy and correctness.