Privacy-Aware Ant Routing for Wireless Multimedia Sensor Networks in Healthcare

The problem of maintaining the privacy of sensitive healthcare data is crucial yet the significance of research efforts achieved still need robust development in privacy protection techniques for Wireless Multimedia Sensor Networks (WMSNs). This paper aims to investigate different privacy-preserving methods for WMSNs that can be applied in healthcare, to guarantee a privacy-aware transmission of multimedia data between sensors and base stations. The combination of ant colony optimization-based routing and hierarchical structure of the network have been proposed in the AntSensNet WMSN-based routing protocol to offer QoS and power efficient multipath multimedia packet scheduling. In this paper, the AntSensNet routing protocol was extended by utilizing privacy-preserving mechanisms thus achieving anonymity / pseudonymity, unlinkability, and location privacy. The vulnerability of standard AntSensNet routing protocol to privacy threats have raised the need for the following privacy attacks' countermeasures: (i) injection of fake traffic, which achieved anonymity, privacy of source and base locations, as well as unlinkability; (ii) encrypting and correlating the size of scalar and multimedia data which is transmitted through a WMSN, along with encrypting and correlating the size of ants, to achieve unlinkability and location privacy; (iii) pseudonyms to achieve unlinkability. The impact of these countermeasures is assessed using quantitative performance analysis conducted through simulation to gauge the overhead of the added privacy countermeasures. It can be concluded that the introduced modifications did enhance the privacy but with a penalty of increased delay and multimedia jitter. The health condition of a patient determines the vitals to be monitored which affects the volumes and sources of fake traffic. Consequently, desired privacy level will dictate incurred overhead due to multimedia transmissions and privacy measures.