Protecting Location Privacy with Dynamic Mac Address Exchanging in Wireless Networks

Abstract

In this paper, we propose a novel dynamic Mac address assignment and exchange strategy to reduce location disclosure risks. The use of dynamic Mac addresses in a local area network (LAN) is feasible since the address uniqueness needs only to be handled within the LAN. Though each node has a universal Mac address assigned by the manufacturer, a local unique Mac address is sufficient for the node to participate in communications. Our proposed strategy includes three major schemes. The first is to assign a Mac address to the client using the same idea as the IP address assignment. Next, a Mac addresses shuffle is conducted among the clients in the wide local area network (WLAN) without exposing any exchange relations or frequently disrupting current connections. Lastly, dummy messages are sent from the wireless client to cover others during idle. In current wireless networking, a client must communicate with an access point (AP) and authorization server in order to obtain authorization to access a local wireless network. In our scheme, we do not use a node's real physical Mac address when associating with an AP. Instead, there is a public special Mac address broadcast in the beacon messages which will be chosen as the source Mac address in the association request frame. As a result, the user will never expose its identifier when associated with the AP. The client also keeps a variant silent period as a defense against a correlation attack.