Tham khảo tài liệu 'current trends and challenges in rfid part 15', kỹ thuật - công nghệ, cơ khí - chế tạo máy phục vụ nhu cầu học tập, nghiên cứu và làm việc hiệu quả | 410 Current Trends and Challenges in RFID Back-end database server Reader Tag 2. h Keyi Q R generates n computes n co n-m ỵ 3. n-m Q 1. Q -1 4. n n m m gets indeXi and R inquires the indexi to find Key h Keyi Q R a h Keyi R Keyi a R 5. a 6. a h Keyt R Fig. 25. Chen s indefinite-indexed access control scheme The motivation of this scheme is to make the tag s response message not predictable to prevent the tracing of individual. In other word the tag s response message in each access cannot be recognized it is emitted by the same tag. In this scheme the tag s serial number is regarded as a coordinate. Infinite possibilities exist to select two un-parallel lines crossed on the coordinate. Therefore the tag s serial number can be represented differently in each access and not useful to identify the tag. Moreover the other messages emitted between the tag and the reader are also randomized and not useful to trace the tag. Therefore the tag s location privacy can be guaranteed. In addition this scheme also guarantees mutual authentication and resists the man-in-the-middle attack the spoofed reader attack and the spoofed tag attack. 4. Conclusions Modern RFID systems are creating a new era of ubiquitous information society. It allows almost everything to be uniquely numbered by embedding a RFID tag. Then the process automation efficiency and usability could be improved Chang 2005 Garfinkel et al. 2005 . It allows objects to be scanned and identified without the need for visual or physical contact. However due to the powerful tracking capability of RFID tag it poses a potentially widespread threat to consumer privacy McCullagh 2003 . In the world of RFID tags widespread deployment anyone with an RFID reader can potentially discover individuals informational preferences without their permission. Without access control anyone can read the information stored on current generation RFID tags. The static unique identifiers stored on tags can be traced for linking the tagged .
