With the rapid spread of various mobile terminals in our society, the importance of secure positioning is growing for wireless networks in adversarial settings. Recently, several authors have proposed a secure positioning mechanism of mobile terminals which is based on the geometric property of wireless node placement, and on the postulate of modern physics that a propagation speed of information never exceeds the velocity of light. In particular, they utilize the measurements of the round-trip time of radio signal propagation and bidirectional communication for variants of the challenge-and-response. In this paper, we propose a novel means to construct the above mechanism by use of unidirectional communication instead of bidirectional communication. Our proposal is based on the assumption that a mobile terminal incorporates a high-precision inner clock in a tamper-resistant protected area. In positioning, the mobile terminal uses its inner clock and the time and location information broadcasted by radio from trusted stations. Our proposal has a major advantage in protecting the location privacy of mobile terminal users, because the mobile terminal need not provide any information to the trusted stations through positioning procedures. Besides, our proposal is free from the positioning error due to claimant's processing-time fluctuations in the challenge-and-response, and is well-suited for mobile terminals in the open air, or on the move at high speed, in terms of practical usage. We analyze the security, the functionality, and the feasibility of our proposal in comparison to previous proposals.
On the other hand, there are location verification protocols which substantially make use of the physical properties of broadcasted radio waves @cite_8 @cite_15 . In @cite_8 , their proposal depends on the intensity and the directivity of broadcasted radio waves for location verification. In @cite_15 , their proposal with duplex radio communication assumes spatial isotropic propagation of radio waves by use of mobile terminal's omni-directional antenna, and uses its particular geometric relation for location verification. But both proposals have a security vulnerability to malicious modification of the assumed physical properties of radio waves. There are many possible ways, especially for a mobile terminal user, to carry out the physical modification of radio waves, e.g., by fraudulently using a directional antenna for the mobile terminal, or by surrounding the mobile terminal with carefully chosen mediums or materials.
@cite_15 @cite_8
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Authentication in conventional networks (like the Internet) is usually based upon something you know (e.g., a password), something you have (e.g., a smartcard) or something you are (biometrics). In mobile ad-hoc networks, location information can also be used to authenticate devices and users. We focus on how a provers can securely show that (s)he is within a certain distance to a verifier. Brands and Chaum proposed the distance bounding protocol as a secure solution for this problem. However, this protocol is vulnerable to a so-called "terrorist fraud attack". In this paper, we explain how to modify the distance bounding protocol to make it resistant to this kind of attacks. Recently, two other secure distance bounding protocols were published. We discuss the properties of these protocols and show how to use it as a building block in a location verification scheme Secure location verification is a recently stated problem that has a number of practical applications. The problem requires a wireless sensor network to confirm that a potentially malicious prover is located in a designated area. The original solution to the problem, as well as solutions to related problems, exploits the difference between propagation speeds of radio and sound waves to estimate the position of the prover. In this paper, we propose a solution that leverages the broadcast nature of the radio signal emitted by the prover and the distributed topology of the network. The idea is to separate the functions of the sensors. Some sensors are placed such that they receive the signal from the prover if it is inside the protected area. The others are positioned so that they can only receive the signal from the prover outside the area. Hence, the latter sensors reject the prover if they hear its signal. Our solution is versatile and it deals with provers using either omni-directional or directional propagation of radio signals without requiring any special hardware besides a radio transceiver. We estimate the bounds on the number of sensors required to protect the areas of various shapes and extend our solution to handle complex radio signal propagation, optimize sensor placement, and operate without precise topology information