Device Identification in the Presence of MAC Randomization

Wi-Fi (IEEE 802.11) is the most-used protocol for wireless internet access on customer premises. The MAC address of each connected device, which used to be static, is being recently randomized (by the device's operating system) as frequently as daily to prevent tracking and fingerprinting of devices and users. While this feature might be useful in public areas, it disturbs some day-to-day functionalities, such as firewalls, parental control, and similar applications that require a static identifier per device. In this work, we present methods to ensure the functionalities of these applications, even when the MAC address is changed every time the device connects to the network. Our methods work even if the latest MAC randomization techniques are applied and provide these device identifications only to the gateway router. (Potentially malicious) devices that are connected to the same LAN, still see the randomized MAC address, and therefore, cannot identify or track the device.