Wi-SL: A Secure Lightweight WiFi Transmission Mechanism for IoT Devices

As Internet of Things (IoT) continues to become popular, there is an increasing number of IoT devices. These IoT devices usually access the Internet through WiFi, the most popular and convenient wireless technology, especially in home and enterprise networks. However, the WiFi protocol mechanism is complicated and not suitable for some weak-ability IoT devices. Thus, it is necessary to design a lightweight transmission mechanism that adapts to these resource-constrained IoT devices. In this paper, we utilize the probe frame stuffing technology to transmit data without association, and design a secure lightweight WiFi transmission mechanism for IoT devices called Wi-SL. In Wi-SL, we achieve two-way communication by stuffing data in the elements of probe request and response frames. Besides, Diffie-Hellman key exchange and AES encryption algorithms are adopted to encrypt data. Finally, we build a Wi-SL testbed including an AP and ten IoT devices to conduct the experiments. The results demonstrate that Wi-SL can achieve two-way data encryption transmission between the clients and the AP. More-over, the overall transmission process is secure, efficient, and energy-saving, which shows that Wi-SL is fully capable of IoT communication scenarios.