Sensor cloud provides a new way for the owners of different WSNs (Wireless Sensor Networks) to share their data to other parties (users/organizations). The edge-computing-assisted sensor-cloud systems (EC-assisted SCSs) can even supply real-time services for different parties. However, both the edge servers and the cloud servers in the systems are prone to be attacked in insecure network environments, since they are the bridges connecting both the end users and the WSNs in EC-assisted SCSs and attacking the servers can bring much more benefits for the attackers than just compromising some sensor nodes. In this paper, the problem of secure Top-$k$ query in EC-assisted SCSs was studied, considering that non-trusted edge servers and non-trusted cloud servers exist in the systems, and a novel scheme was proposed to solve the problem. To achieve privacy preservation of the sensed data items and their scores, a secure key distribution protocol was designed, and some data-processing or integrity verification algorithms were also developed in the proposed scheme to preserve the data integrity of the query results. Thorough security analyses and extensive simulations show that the proposed scheme is efficient and secure, and it is perfectly fit for Top-$k$ query in EC-assisted SCSs.

传感器云为不同 WSN（无线传感器网络）的所有者提供了一种新的方式来将他们的数据共享给其他方（用户/组织）。边缘计算辅助传感器云系统（EC 辅助 SCS）甚至可以为不同方提供实时服务。然而，系统中的边缘服务器和云服务器在不安全的网络环境中都容易受到攻击，因为它们是连接EC辅助SCS中最终用户和WSN的桥梁，攻击服务器可以带来更多好处对于攻击者来说，不仅仅是妥协一些传感器节点。在本文中，安全Top-$克$考虑到系统中存在不可信边缘服务器和不可信云服务器，研究了EC辅助SCS中的查询，并提出了一种新的方案来解决该问题。为了实现感知数据项及其分数的隐私保护，设计了一种安全的密钥分发协议，并在所提出的方案中开发了一些数据处理或完整性验证算法，以保护查询结果的数据完整性。彻底的安全分析和广泛的模拟表明，所提出的方案高效且安全，非常适合 Top-$克$ 在 EC 辅助的 SCS 中查询。