Privacy Enhanced and Light Weight RFID System without Tag Synchronization and Exhaustive Search

Radio frequency identification systems (RFID systems) are becoming popular in various applications, such as supply chain management, animal husbandry and so on. They are useful to manage not only things but also living things. Privacy, however, must be taken in account when they are used around people since people with RFID tags can easily be tracked and traced. While several solutions have been proposed to solve this problem, they have drawbacks that the back-end servers (or the readers) must exhaustive-search all the registered IDs to identify the RFID tags and/or that database must synchronize with the tags. The former is not desirable when a huge number of RFID tags must be managed, and the latter is not desirable when restoring database from backup (since tags and the database are not synchronous after restoration). In this paper, we propose how to solve these problems without deteriorating the privacy protection ability.