Modeling the tradeoff between eavesdropping and network lifetime through a mixed integer programming approach in underwater acoustic sensor networks

Although there are plenty of research on wireless sensor networks in the terrestrial environment, there are relatively little research on underwater acoustic sensor networks (UASNs). In recent years, UASNs attract considerable attention for a variety of reasons. Because of the characteristic differences of the underwater environment, the studies conducted in terrestrial environment cannot be directly applied to UASNs. In UASNs, acoustic communication is preferred rather than electromagnetic and optical communication which cannot work efficiently in underwater. UASNs are often placed in severe environments and therefore they face many safety hazards. Moreover, because of the harsh characteristics of the underwater environment, they are vulnerable to hostile attacks. One of the most dangerous security threats is the eavesdropping attack where an attacker node silently taps the information exchanged between the sensor nodes. While careful assignment of transmission power levels and optimization of data flow paths can help mitigate the scope of eavesdropping attacks, it can negatively impact network lifetime. In this study, two optimization models are proposed where the first model minimizes the eavesdropping risk in UASNs while the second model maximizes network lifetime under a precise level of an eavesdropping risk. The results show that the networks lifetime obtained when eavesdropping risk is minimized are considerably shorter than the network lifetime obtained in the absence of eavesdropping constraint. Similarly, when the precautions against the eavesdropping risks are relaxed, network lifetime in UASNs increases significantly.