Identifying Mobiles Hiding Behind Wireless Routers

The Network Address Translation technique (NAT) is widely used in wireless routers. It is a low cost solution to IPv4 address space limitations. However, cyber criminals may abuse NAT and hide behind wireless routers to use mobile devices and conduct crimes. To identify a suspect mobile device, the authors should be able to map the suspect public traffic on the Internet to the private traffic behind the wireless router in WLAN. In this paper, they propose a suite of novel packet size based traffic marking techniques to identify suspect mobiles in encrypted wireless networks as well as open wireless networks.