摘要:无线射频识别技术(Radio Frequency Identification)是一种非接触的自动识别技术，它利用射频信号通过空间耦合实现无接触信息传递并通过所传递的信息达到识别的目的。RFID射频识别技术应用十分广泛，其最为突出的优点在于，可以进行非接触的远程读取，并且不需要人工操作，可以工作在恶劣环境中。

　　　现今RFID技术的应用领域越来越广阔，如服务行业、制造企业、购买与销售物流、身份识别等，而随之带来的严重问题是其安全隐私上的脆弱，如标签信息容易被窃取、篡改等，这也是目前一个急需解决的问题。如果RFID安全隐私问题解决不当，那么其应用范围将被大大缩减。

　　　本文首先介绍RFID安全技术的研究背景和RFID安全问题的国内外研究现状，然后介绍单钥以及双钥体制，以及其中一些重要的加解密算法和数字签名算法，同时给出实验结果。然后阐述了一种已提出的RFID安全协议LMAP，将实验结果进行演示，并对其进行安全分析，指出其存在的安全隐患，之后提出一个基于非同步攻击问题的改进方案。最后，将改进的RFID安全协议LMAP的实验结果进行演示，验证改进方法的可行性。

关键词：RFID ，加密解密算法，数字签名算法，安全协议，非同步攻击

Abstract:RFID (Radio Frequency Identification) is a non-contact automatic identification technology .It uses radio frequency through space coupling that enables wireless data transmission and can identify objects. RFID is very popular in some areas, It’s most prominent advantage is that it can undertake non-contact remote read, and does not require manual operation , RFID can also work in a variety of adverse circumstances.

　　In recently years, RFID systems have become very popular in applications such as service industries, manufacturing companies, purchasing and distribution logistics, human identification ,etc .But the serious problem coming with it is its weakness on security, such as the data in the tag can be eavesdropped or falsified easily ,this is an urgent problem now. If the problem can not be solved well , its application would have some limitations.

　　This article first introduces the background and the current status of RFID ,then introduces one-key cryptosystem and two-key cryptosystem, and some classical encryption algorithms and digital signature algorithms ,at the same time, experimental results are given .Then the article introduces the proposed RFID security protocol called LMAP，and shows the experimental results, this article also analyzes the security problems of LMAP, points out its potential safety problems ,and proposes a solution based on the De-synchronization Attack. At last, the experimental results of the newly developed RFID security protocol are given for verifying its feasibility.

Keywords：RFID, encryption and decryption algorithm , digital signature algorithm ,security protocol ,De-synchronization attack