Hidetoshi Kido

Recently, highly accurate positioning devices enable us to provide various types of location-based services. On the other hand, because such position data include deeply personal information, the protection of location privacy is one of the most significant problems in location-based services. In this paper, we propose an anonymous communication technique to protect the location privacy of the users of location-based services. In our proposed technique, such users generate several false position data (dummies) to send to service providers with the true position data of users. Because service providers cannot distinguish the true position data, user location privacy is protected. We also describe a cost reduction technique for communication between a client and a server. Moreover, we conducted performance study experiments on our proposed technique using practical position data. As a result of the experiments, we observed that our proposed technique protects the location privacy of people and can sufficiently reduce communication costs so that our communication techniques can be applied in practical location-based services.

Recently, highly accurate positioning devices enable us to provide various types of location-based services. On the other hand, because position data obtained by such devices include deeply personal information, protection of location privacy is one of the most significant issues of location-based services. Therefore, we propose a technique to anonymize position data. In our proposed technique, the psrsonal user of a location-based service generates several false position data (dummies) sent to the service provider with the true position data of the user. Because the service provider cannot distinguish the true position data, the user’s location privacy is protected. We conducted performance study experiments on our proposed technique using practical trajectory data. As a result of the experiments, we observed that our proposed technique protects the location privacy of users.

In this paper, we introduce location traceability as an indicator for evaluating time-series location privacy for users on location-based services (LBS). The location traceability of a user is calculated with a formalized tree structure that represents all possible paths of a moving user. Through the results of the simulation experiments, we validated the effectiveness of this proposed indicator

In this paper, we introduce location traceability as an indicator for evaluating time-series location privacy for users on location-based services (LBS). The location traceability of a user is calculated with a formalized free structure that represents all possible paths of a moving user. Through the results of the simulation experiments, we validated the effectiveness of this proposed indicator

Information types distributing in the internet include character map and picture as well as audio Among these, map information is predicted to increase with various purposes and many contents because of the following features: a) Map itself includes large some can't be transmitted without map data, b) Providing map information lets users comprehend information contents more easily, and c) Plentiful services can be realized by means of GPS (Global Positioning System) connecting with map Now there is various map information in the internet, such as information, information, route situation information, as well as tourist information. Meanwhile there are some problems and impediments on handling map information for both users and information providers (road administrators). In order to solve these problems, a measure that is the core technology in Sapporo ITS is proposed in this paper, at the same time the road and traffic information system utilizing XML technology of Sapporo ITS is introduced. For the covering abstract see ITRD E114174.