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UBC Theses and Dissertations

Security, privacy and efficiency in RFID systems Vahedi, Ehsan


Radio frequency identification (RFID) is a ubiquitous wireless technology that allows objects to be identified automatically. Using the RFID technology can simplify many applications and provide many benefits but meanwhile, the security and privacy of RFID systems should be taken into account. In this thesis, we have two goals. The first one is to improve the security and privacy in RFID systems. Our second goal is to provide accurate analytical models for the most important tag singulation schemes. We use these analytical models to evaluate and compare the efficiency of the tag singulation schemes. First, we study the blocking attack in RFID systems and develop an analytical model for it. Using this analytical model, we propose two probabilistic blocker tag detection (P-BTD) algorithms for RFID systems that operate based on the binary tree walking and ALOHA techniques. Then, we study the security and privacy of some recently introduced light-weight authentication protocols, and discuss their advantages and drawbacks. Based on this analysis and considering the hardware limitations of RFID tags, we propose a new authentication protocol that improves the security and privacy in RFID systems. By taking advantage of the analytical model we proposed for the ALOHA-based P-BTD algorithm, we develop an accurate tag estimate method. Using the proposed method, we can estimate the number of tags in RFID systems accurately, and design more efficient ALOHA-based tag singulation mechanisms. Next, we study the EPC Gen-2 protocol and its tag singulation mechanism. We model the EPC Gen-2 protocol as an absorbing Markov chain. Using the model proposed, we derive accurate analytical expressions for the expected number of queries and the expected number of transmitted bits needed to identify all tags in the RFID system. Finally, we study the use of the CDMA technique for RFID systems. We model the CDMA-based tag singulation procedure as an absorbing Markov chain, and derive accurate analytical expressions for the expected number of queries and the amount of transmitted data needed to identify all tags in the system. Using the analytical models developed, we compare the performance of the CDMA-based and the EPC Gen-2 tag singulation schemes.

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