Research Of Anti-collision Algorithm And Security Protocol In RFID Systems

Radio frequency identification (RFID) is the core technology of Internet of things,which is a non-contact automatic identification technology, also called electronic tagtechnology. A complete RFID system consists of three parts: readers, tags and datamanagement system in the backend. The wireless communication is realized by sending aradio signal, so as to recognize specific objects and obtain related data. With the rapiddevelopment of radio frequency identification technology, it has been applied in warehousemanagement, Electronic Toll Collection and medical equipment management.The way of wireless communication brings convenience to identification; however, italso brought some urgent technical problems at the same time. For example, when multipletags communicate with one reader simultaneously, data collisions will decrease theefficiency of communication, and even destroy the integrity and accuracy of theinformation. Tag anti-collision algorithm is just to solve this problem. On the other hand,how to ensure that the readers have access only to the legitimate tags and have the ability ofidentifying illegal tags, and how to guarantee that the information on the tags is not read bythe illegal readers. This is what security authentication protocols study about.This paper summarizes two kinds of existing anti-collision algorithms. On this basis,we present a series of new approaches which combine framed slotted ALOHA and binarytree. As a result, our algorithms achieve less time and energy consumption, especially suitfor handheld readers. From simulation, we verify that the self-adaption framed binarysearch algorithm (SA-FBS) has the distinguished advantages contrasting with traditionalanti-collision algorithms. Moreover, after analyzing the existing Privacy-PreservingAuthentication (PPA) methods for RFID systems, we propose a kind of PPA based onPublic-Key Cryptography Standards. It encrypts data with public key in the tags anddecrypts the cipher texts with private key in the backend database. In this way tags andreaders realize authentication mutually. From analyzing, we verify our protocol has goodperformance on resisting attacks. In order to improve the execution efficiency, we employ asparse tree to organize tags in the database, which avoids the numerous computation oflinear search in the database. The time complexity is reduced from O(N) to O(log_qN).