Abstract
Recently, many types of RFID products has been developed and used to tightly bind the ID tag to users? personal information in an application. This has brought up new social problems where RFID tags can be detected from other RFID readers without the user being conscious of the transaction. In this paper, we provide a location management system named Tachyon. Tachyon defines policy files which describe the privacy of the user?s location information. In Tachyon, users can expose their location information with a privacy policy. Additionally, Tachyon can reduce the cost of building distributed location management system.