Multi-Level Dynamic Key Management for Scalable Wireless Sensor Networks with UAV

Wireless Sensor Networks (WSNs) are more vulnerable to security attacks than wired networks because of their wireless and dynamic nature. In today’s WSNs, the sensor nodes act not only as routers but also as communication endpoints, and they are also responsible for the security of the messages. Therefore, it is important to define whether an incoming message originates from a trustworthy node or not. The main solution for this is the usage of cryptographically signed messages. There are two main classifications for signing messages: namely symmetric and asymmetric algorithm based cryptography. In the asymmetric key cryptography, public/private key pairs are used to encrypt and decrypt messages. However, it can cause severe computational, memory, and energy overhead for the nodes. On the other side, symmetric key cryptography is superior to asymmetric key cryptography in terms of speed and low energy cost, but at the same time, it needs to design an efficient and flexible key distribution schemes for improving system performance. In this paper, it is aimed to set a multi-level dynamic key management system for WSNs with the aid of an Unmanned Aerial Vehicle (UAV) as a key distribution and coordination center for asymmetric keys. Public keys of the sensor nodes are dispatched by UAVs and symmetric keys set with these key combinations. Evaluation results show the proposed system is scalable, and its performance is considerably better than single asymmetric key management systems