Research On Some Problems In The Identification Of Passive RFID Tags

The Internet of Things has become one of the strategic commanding heights in theeconomy and technology development of the current world. Radio frequency identification isa key technology in IOT. It transmits and obtains information via radio to identify objects. AnRFID system mainly consists of RFID tags, RFID readers and a back-end server. PassiveRFID tags are usually attached to or embedded in objects so that the object or the carrier canbe identified. Being the carrier of information, tags play a very important role in RFIDsystems. By identifying the tag, the reader can obtain the features of the object or theinformation of the owner.There are several problems in the identification of the passive RFID tags, includingcollision problems, security problems and search problems. These problems restrict thelarge-scale use of RFID tags. So we study these problems in this dissertation, presentcomputation, proof and data in theory, make these theoretical results directly work in thepractical use by integrating the actual RFID tag hardware and RFID standards, and solve theproblems in the identification of passive RFID tags to promote the application of RFIDtechnology and the development of IOT.This dissertation makes a relatively thorough research on the identification of passiveRFID tags and obtains several achievements. The main research content and results in thisdissertation are as follows:1. Make unified description of the problems in the identification of passive RFID tags, i.e. collision problems, security problems and search problems. Search problems can beregarded as the combination of collision problems and security problems. The descriptionincludes the situation of the problem, the objective to be achieved, the existing obstacles andthe requirements to be satisfied to reach the goal.2. Make a detailed review and analysis of the state of the art of RFID tag anti-collision algorithms. Propose a temporary ID based query tree RFID tag anti-collision algorithm. Eachtag in this algorithm selects a sequence from its ID as its temporary ID. When several tags areundistinguishable because of the same temporary ID, they will select other sequences in ID.The simulation results show that the algorithm has advantage over the query tree algorithmand its variants in terms of average number of transmitted bits for one tag identification. Sothe algorithm improves the identification efficiency. Propose a bi-slotted binary tree RFID taganti-collision algorithm with stack. Manchester code is used in this algorithm. Bi-slottedmechanism is adopted to reserve slots for the tag responses so that the average number oftransmitted bits by the tag and the number of collisions will be reduced. The reader maintainsa stack to record the position of collisions so that the number of queries sent by the reader isreduced and the useless repeated queries are dimished. Mathematical derivation andsimulation results both prove that the proposed algorithm outperforms the original binary treealgorithm in terms of time complexity and communication complexity and provide betterperformance on tag identification.3. Analyze the design of a lightweight stream cipher named Trivium, destruct it toTrivium-model shift registers and generalize the structure to k rounds. Prove that thecharacteristic polynomial of a k-round Trivium-model shift register has the format of (1+x)kf(x) and define k-order primitive polynomials. Give the design criteria of Trivium-modelstream ciphers, requiring the characteristic polynomials of each round to be k-order primitivepolynomials. Based on the criteria, an improved version of Trivium is presented. Moreover, anew RFID tag oriented lightweight stream cipher, Quavium, is proposed. Quavium iscomposed of4-round Trivium-model shift registers and each round satisfies the k-orderprimitive polynomial so that the stream cipher can be used in a shorter version or in thecomplete version according to different application requirements. Experimental results showthat Quavium performs nearly the same as Trivium in both hardware and software. Quaviumof fewer rounds have better performance and is more suitable for the communication securityof passive RFID tags.4. Study the simple RFID authentication protocols, the lightweight RFID authenticationprotocols and the ultralightweight RFID authentication protocols respectively. In the simpleRFID authentication protocols aspect, a typical anonymous RFID authentication protocolARAP is analyzed and impersonation attack is launched against this protocol. According tothe computation complexity requirements of simple protocols, a new operation named permutation is introduced and corresponding remedies are presented to improve the originalversion and resist impersonation attacks. In the lightweight RFID authentication protocolsaspect, a generalized3-round lightweight RFID mutual authentication protocol framework ispresented. It is proved that if the protocol framework is vulnerable to impersonation attacks,desynchronization attacks can also be launched against it. Based on this theorem,desynchronization attacks are launched against two lightweight RFID mutual authenticationprotocols in conformity with EPC C1G2standards. In addition, corresponding suggestions areproposed to change the computation of the messages sent by tags so as to resistdesynchronization attacks. In the ultralightweight RFID authentication protocols aspect, anultralightweight RFID authentication protocol with permutation is analyzed. Some theoremsrelated to the permutation and left rotation operations are proposed. It is pointed out thatultralightweight protocols have vulnerabilities due to the fact that tags cannot generaterandom numbers. Therefore, initial value mechanism is introduced to provide freshness in thetag end. An enhanced ultralightweight RFID authentication protocol is proposed and securityanalysis and performance evaluation are given.5. Propose the design criteria for lightweight RFID search protocols and design aserverless lightweight RFID tag search protocol conforming to EPC C1G2standards.Compared with other search protocols, the proposed protocol requires fewer operation typesand less computation complexity. So it is more suitable for passive RFID tag search. Securityanalysis shows that the protocol achieves data integrity, entity authentication, entityanonymity and untraceability.