In this paper we present a technique to create WLAN device fingerprints by measuring timing properties without the use of special-purpose hardware. Our proposed process is absolutely passive and cannot be detected by the targeted device. The timing measurement is based on a delay caused by the hardware implementation of the CRC checksum algorithm at the network interface card (NIC) of the client. This delay turned out to be significant for a large number of different chipset implementations. The ability of identifying connected devices could improve the security of a wireless network significantly. It could help to enhance access control mechanisms and would deliver valuable real time information about the connected clients. As a proof of our concept we present a prototype implementation called WiFinger to evaluate our approach.
['Guenther Lackner', 'Peter Teufl']
IEEE 802.11 chipset fingerprinting by the measurement of timing characteristics