In this paper, we consider user location privacy in mobile edge clouds (MECs). MECs are small clouds deployed at the network edge to offer cloud services close to mobile users, and many solutions have been proposed to maximize service locality by migrating services to follow their users. Co-location of a user and his service, however, implies that a cyber eavesdropper observing service migrations between MECs can localize the user up to one MEC coverage area, which can be fairly small (e.g., a femtocell). We consider using chaff services to defend against such an eavesdropper, with focus on strategies to control the chaffs. Assuming the eavesdropper performs maximum likelihood (ML) detection, we consider both heuristic strategies that mimic the user's mobility and optimized strategies designed to minimize the detection or tracking accuracy. We show that a single chaff controlled by the optimal strategy or its online variation can drive the eavesdropper's tracking accuracy to zero when the user's mobility is sufficiently random. We further propose extended strategies that utilize randomization to defend against an advanced eavesdropper aware of the strategy. The efficacy of our solutions is verified through both synthetic and trace-driven simulations.
@cite_21: The broadcast and tetherless nature of wireless networks and the widespread deployment of Wi-Fi hotspots makes it easy to remotely locate a user by observing her wireless signals. Location is private information and can be used by malicious individuals for blackmail, stalking, and other privacy violations. In this paper, we analyze the problem of location privacy in wireless networks and present a protocol for improving location privacy. Our basic approach is to obfuscate several types of privacy-compromising information revealed by a mobile node, including sender identity, time of transmission, and signal strength. Our design is driven by real-system implementation and field experiments along with analysis and simulations. Our system allows users to choose the level of privacy they desire, thereby increasing the performance of less private users (while not sacrificing private users' privacy at the same time). We evaluated our system based on real-life mobility data and wireless LAN coverage. Our results show that a user of our system can be indistinguishable from a thousand users in the same coverage area.
@cite_2: Abstract Though an increasing number of wireless hotspots and mesh networksare being deployed, the problem of location privacy has been ignored.When a user’s location privacy is compromised, an attacker can deter-mine where the user is, and use this information, for example, to stalkor blackmail the user. In existing systems, a user’s location can beeasily inferred from the signal strengths of packets transmitted fromher x ed address. Even if an attacker cannot decode packet contentsand addresses, he can correlate different transmissions using a modelof the user’s movement. In this paper, we argue that location privacymust be a rst-class citizen in the design of a wireless communica-tions system. We build a transaction -based wireless communicationsystem in which transactions (a single request-response exchange be-tween two nodes) are unlinkable ; that is, they cannot be correlated.We nd that it is even possible to support real-time session-based ser-vices such as Voice-over-IP on top of transaction primitives, thoughwith weaker privacy properties. We also identify a number of chal-lenges in providing location privacy in the areas of routing, incentivesfor multi-hop forwarding, and user- and application-driven tuning ofthe privacy-performance tradeoff.
Besides the direct channel, can also release location information. An important side channel in wireless networks is the transmission activity, which can be monitored by a wireless eavesdropper to track the user. To defend against wireless eavesdropping, mechanisms are proposed to protect senders receivers using anonymous routing protocols, frequently changing pseudonyms, silent periods, and reduced transmission power @cite_2 @cite_21 . The above mechanisms are in that they modify the user's behavior. In contrast, we study another side channel arising in MECs due to correlated user mobility and service mobility, and propose a defense mechanism using chaffs.