Research On Anti-Collision Algorithm And Security Authentication Protocol In RFID

RFID (Radio Frequency Identification, RFID) is the non-contact communication technology which use radio frequency signals to automatically identify a specific target to read and write relating information. In the RFID system, the electronic tag attached to the article which will be identified stores a unique identifier. The reader identifies the article with an identification tag by transmitting radio frequency signals. However, in the RFID system, the problem of signal interference is existed in the communicating process, especially when some electronic tags response the same reader at the same time and they will result in collision, interfering the recognition process in a great degree. Meanwhile, RFID system has some security risks in the communicating process, such as eavesdropping, counterfeiting, illegal reading, retransmission, desynchronization attack. With the rapid development and wide application of RFID key technologies, anti-collision algorithms and security authentication protocols have become the hot researching topic in the RFID system.Firstly, paper discourses the structure and classification of RFID system, studying and analysing the existed RFID tag anti-collision algorithms, discussing security issues and related security policies in the RFID system.Paper proposes binary search tree anti-collision algorithm based on stack storage, which based on the analysis of binary search tree anti-collision algorithm and combined the "last in, first out" feature of the stack. The algorithm stores the current colliding query command by establishing a stack in the reader. When tags have happened information colliding, the current reader’s query command is pushed in the stack; when a tag is identified successfully, the reader executes pulling stack. By using the "LIFO" feature of stack, achieving query commands’traceability. By compared with the traditional binary search tree anti-collision algorithm to analyse and simulate in throughput and recognition efficiency, the performance of the algorithm has a great increase.Paper combines the frame slotted ALOHA algorithm and binary search tree algorithm, and complexes the features of them, proposes the anti-collision algorithm based on frame-grouping and binary search tree to identify. Firstly, the algorithm identifies tags by frame slotted ALOHA algorithm in the first stage, and divides tags which not be identified into several groups based on colliding slots, then uses binary search tree algorithm to certainly identify each group in the second stage. By compared with the traditional frame slotted ALOHA algorithm and binary search tree anti-collision algorithm to analyse and simulate in throughput and recognition efficiency, the performance of the algorithm has a great increase.Paper proposes a kind of security authentication protocol based on Hash and status-locked, which based on Hash functions related protocols and the symmetric key mechanism. The protocol uses Hash function and symmetric encryption method, combines the setting of status-locked in back-end database and tags, updates the values of ID and key after the authentication, effectively deal with security risks in RFID authentication stage. The analysis of security shows that the protocol not only ensures the tags’ anonymity, integrity and confidentiality, but also resists the attacks of attackers’ fake, retransmission and desynchronization, can be better to complete the authentication of reader and tags in the RFID system.