Improved C-Language Implementation of AES Algorithm for WSN

Various IoT applications use wireless sensor networks (WSN) that require secured communication links in order to avoid cyberattacks. WSN interconnects numerous sensors that acquire specific parameters for different applications such as environment monitoring, health supervising, perimeter security and safety and so on. The sensor node can encrypt data onboard in order to ensure information security. Every sensor node has limited resources and processing capacity. AES is a very powerful encryption algorithm that can use private encryption keys of 128, 192 or 256 bits. For WSN, Arduino is a good option to implement a sensor node with temperature, relative humidity, pressure, light, air quality and/or gas sensors. The sensors acquire the environmental parameter values. Then, they sent them by the communication link to a central node, in order to store and analyze them. It is important to send information encrypted not as a plain text, by the mean of an encryption algorithm. We choose to implement Advanced Encryption Standard (AES) in C programming language, with various improvements of the algorithm itself. The program runs on a dual Arduino Due-based system with multiple sensors for environmental monitoring.