Abstract

Securing the wireless Internet of Things (IoT) is a complex challenge due to devices’ computing capacity limitations, battery restrictions or insufficient power supply. Reaching 30 billion connected devices in 2020, the IoT sector is booming. According to marketing studies, by 2025, the global IoT market is expected to reach $34.4 billion and the global IoT battery market is estimated to growth to $15.8 billion. Nevertheless, the smart city, connected healthcare, Industry 4.0 and home security, representing over 75% of the IoT market, raise critical cybersecurity and energy consumption issues. The battery lifespan of specific devices such as Wireless Sensor Networks (WSNs), Wearable or Implantable Medical Devices (WMDs, IMDs) can then be drastically impacted. To meet emerging demands, new solution to provide both cybersecurity and energy efficiency must be developed. Hence, this thesis research tried to develop a dynamic and secure solution to balances communication security and power consumption according to the IoT device's current battery level and the reduced-round cryptography. The contributions are as follow: (1) the security and power consumption evaluation of reduced-round cryptography on different lightweight ciphers; (2) the design, and implementation of a dynamic mechanism to control the battery discharge by adjusting the communication encryption cipher reduced-round value; (3) the design, integration and evaluation of our dynamic reduced-round mechanism integrated within TLS protocol version 1.2 and 1.3. The results of the two experiments confirm the efficiency of the reduced-round cryptography and of our dynamic round-reduced TLS extension to achieve a trade-off between IoT's communications security level and energy savings.