Usually, a proof of a theorem contains more knowledge than the mere fact that the theorem is true. For instance, to prove that a graph is Hamiltonian it suffices to exhibit a Hamiltonian tour in it; however, this seems to contain more knowledge than the single bit Hamiltonian/non-Hamiltonian.In this paper a computational complexity theory of the “knowledge” contained in a proof is developed. Zero-knowledge proofs are defined as those proofs that convey no additional knowledge other than the correctness of the proposition in question. Examples of zero-knowledge proof systems are given for the languages of quadratic residuosity and 'quadratic nonresiduosity. These are the first examples of zero-knowledge proofs for languages not known to be efficiently recognizable.

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The knowledge complexity of interactive proof-systems

Vehicular networks are very likely to be deployed in the coming years and thus become the most relevant form of mobile ad hoc networks. In this paper, we address the security of these networks. We provide a detailed threat analysis and devise an appropriate security architecture. We also describe some major design decisions still to be made, which in some cases have more than mere technical implications. We provide a set of security protocols, we show that they protect privacy and we analyze their robustness and efficiency.

/pdf/securing-vehicular-ad-hoc-networks-4sgegi8hgk.pdf

Securing vehicular ad hoc networks

There has been significant interest and progress in the field of vehicular ad hoc networks over the last several years. VANETs comprise vehicle-to-vehicle and vehicle-to-infrastructure communications based on wireless local area network technologies. The distinctive set of candidate applications (e.g., collision warning and local traffic information for drivers), resources (licensed spectrum, rechargeable power source), and the environment (e.g., vehicular traffic flow patterns, privacy concerns) make the VANET a unique area of wireless communication. This article gives an overview of the field, providing motivations, challenges, and a snapshot of proposed solutions.

/pdf/a-tutorial-survey-on-vehicular-ad-hoc-networks-1kddlbkcs2.pdf

A tutorial survey on vehicular ad hoc networks

Vehicular networking has significant potential to enable diverse applications associated with traffic safety, traffic efficiency and infotainment. In this survey and tutorial paper we introduce the basic characteristics of vehicular networks, provide an overview of applications and associated requirements, along with challenges and their proposed solutions. In addition, we provide an overview of the current and past major ITS programs and projects in the USA, Japan and Europe. Moreover, vehicular networking architectures and protocol suites employed in such programs and projects in USA, Japan and Europe are discussed.

Vehicular Networking: A Survey and Tutorial on Requirements, Architectures, Challenges, Standards and Solutions

The Internet of Things vision: Key features, applications and open issues

: In vehicular ad hoc networks (VANET), it is possible to locate and track a vehicle based on its transmissions, during communication with other vehicles or the road-side infrastructure This type of tracking leads to threats on the location privacy of the vehicle's user In this paper, we study the problem of providing location privacy in VANET by allowing vehicles to prevent tracking of their broadcast communications We first, identify the unique characteristics of VANET that must be considered when designing suitable location privacy solutions Based on these observations, we propose a location privacy scheme called CARAVAN, and evaluate the privacy enhancement achieved under some existing standard constraints of VANET applications, and in the presence of a global adversary

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CARAVAN: Providing Location Privacy for VANET

Communication messages in vehicular ad hoc networks (VANET) can be used to locate and track vehicles. While tracking can be beneficial for vehicle navigation, it can also lead to threats on location privacy of vehicle user. In this paper, we address the problem of mitigating unauthorized tracking of vehicles based on their broadcast communications, to enhance the user location privacy in VANET. Compared to other mobile networks, VANET exhibits unique characteristics in terms of vehicular mobility constraints, application requirements such as a safety message broadcast period, and vehicular network connectivity. Based on the observed characteristics, we propose a scheme called AMOEBA, that provides location privacy by utilizing the group navigation of vehicles. By simulating vehicular mobility in freeways and streets, the performance of the proposed scheme is evaluated under VANET application constraints and two passive adversary models. We make use of vehicular groups for anonymous access to location based service applications in VANET, for user privacy protection. The robustness of the user privacy provided is considered under various attacks.

/pdf/amoeba-robust-location-privacy-scheme-for-vanet-gvvitlo116.pdf

AMOEBA: Robust Location Privacy Scheme for VANET

In wireless networks, the location tracking of devices and vehicles (nodes) based on their identifiable and locatable broadcasts, presents potential threats to the location privacy of their users. While the tracking of nodes can be mitigated to an extent by updating their identifiers to decorrelate their traversed locations, such an approach is still vulnerable to tracking methods that utilize the predictability of node movement to limit the location privacy provided by the identifier updates. On the other hand, since each user may need privacy at different locations and times, a user-centric approach is needed to enable the nodes to independently determine where/when to update their identifiers. However, mitigation of tracking with a user-centric approach is difficult due to the lack of synchronization between updating nodes. This paper addresses the challenges to providing location privacy by identifier updates due to the predictability of node locations and the asynchronous updates, and proposes a user-centric scheme called Swing that increases location privacy by enabling the nodes to loosely synchronize updates when changing their velocity. Further, since each identifier update inherently trades off network service for privacy, the paper also introduces an approach called Swap, which is an extension of Swing, that enables the nodes to exchange their identifiers to potentially maximize the location privacy provided by each update, hence reducing the number of updates needed to meet the desired privacy levels. The performance of the proposed schemes is evaluated under random and restricted pedestrian mobility.

Swing & swap: user-centric approaches towards maximizing location privacy

A century of revolutionary growth in aviation has made global travel a reality of daily life. Aircraft and air transport overcame a number of formidable challenges and hostilities in the physical world. Success in this arduous pursuit was not without leveraging advances of the “cyber” layer, i.e., digital computing, data storage and networking, and software, in hardware, infrastructures, humans, and processes, within the airframe, in space, and on the ground. The physical world, however, is evolving continuously in the 21st century, contributing traffic growth and diversity, fossil fuel and ozone layer depletion, demographics and economy dynamics, as some major factors in aviation performance equations. In the next 100 years, apart from breakthrough physical advances, such as aircraft structural and electrical designs, we envision aviation's progress will depend on conquering cyberspace challenges and adversities, while safely and securely transitioning cyber benefits to the physical world. A tight integration of cyberspace with the physical world streamlines this vision. This paper proposes a novel cyber-physical system (CPS) framework to understand the cyber layer and cyber-physical interactions in aviation, study their impacts, and identify valuable research directions. This paper presents CPS challenges and solutions for aircraft, aviation users, airports, and air traffic management.

Krishna Sampigethaya

Papers

CARAVAN: Providing Location Privacy for VANET

AMOEBA: Robust Location Privacy Scheme for VANET

Swing & swap: user-centric approaches towards maximizing location privacy

Aviation Cyber–Physical Systems: Foundations for Future Aircraft and Air Transport

A framework and taxonomy for comparison of electronic voting schemes