通信工程文献翻译——1.摘要

自从发动机防盗锁止系统（Immobilizer system）的推出以来,对安全的改进需求正在急速增加。 因为其独特的特征，很多反偷窃系统都利用射频鉴定(RFID)技术。 RFID标签能以低成本来提供高水平的安全保护。

这篇文章描述了第1 和2代的发动机防盗锁止系统的系统分析法。 它比较了各种各样的安全级别并且概述了关于最新一代的技术，叫做加密标签。

2.背景

在1993年期间全世界的汽车偷窃量达到了一个保险公司所不能接受的数量。 德国保险公司强制使用了一种新形式安全系统-发动机防盗锁止s的迅捷技术。 在其它领域象政府机构那样的各种各样的组织里也开始将更多的重点放在车辆安全上。 

在较短的时间之内，汽车工业发展了各种各样的系统以阻止窃贼进入或启动车辆。 而选择的方式取决于各国消费者的不同偏好。例如远距离无匙开启在美国和法国更受迎欢，就如透明系统广泛地在德国市场上使用。 由于RFID的独特的特征以及这项技术已经用于工业应用的事实， 大多数的汽车工业决定使用低成本但可提供高安全水平的小型无源标签。 

自从1995年开始，欧洲市场上的产品差不多全部开始装有OEM 发动机防盗锁止s。德国保险公司的第一个统计分析显示了这些系统的巨大成功。 装有电子发动机防盗锁止s的车辆其失窃率大约减少到没有装发动机防盗锁止的车辆的10分之1。

但是犯罪组织有各种的方法和资源来发展高级复杂的设备以破解现有的系统。 安全设备的长久的改进必须要更领先一步。这篇文章描述了基于密钥的发动机防盗锁止s系统不同的安全级别并且提出了能提供RFID 最高安全水平的新一代隐蔽标签。 

3.发动机防盗锁止系统概述

基于密钥的发动机防盗锁止系统由4 组主要部件组成。 系统的核心是标签，是一个可存在于各种各样的组件里且有着不同功能性的无源装置。 如果要运行，标签必须由一个外部能源来提供能量。阅读器产生一个由天线线圈发射出去的高频磁场。 这个能量用来启动标签，并以调制RF信号的形式来传送数据流。 这个信号是通过阅读器收发，然后传给控制器进行数据处理。 

在市场上已经确立了各种不同物理原理的RFID 系统。根据能量传递的不同，两种不同的系统可以被区分开来。 

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1. Abstract

Since the introduction of immobilizer systems the need for improved security constantly increases. Many Anti Theft Systems make use of Radio Frequency Identification (RFID) technology because of its unique features. RFID transponders can provide a high level of security at low cost.

This article describes the system approaches for the first and second generation of immobilizer systems. It compares the various security levels and gives an overview about the latest generation technology, called crypto-transponders.

2. Introduction

During 1993 the worldwide increases in automotive theft reached a level which was no longer acceptable for insurance companies. The German insurance companies forced the rapid introduction of a new form of security systems -immobilizers. In other regions various forces such as government agencies also started placing more emphasis on vehicle security.

During a short time frame the automotive industry developed various systems to prevent thieves from entering and/or starting the vehicle. The methods chosen vary from country to country depending on consumer preferences.

Remote keyless entry for example is preferred in the USA and in France whereas transparent systems are widely spread in the German market. Due to the unique features of RFID and due to the fact that this technology was already existing for industrial applications, most of the automotive industry decided to make use of small batteryless transponders which offer a high level of security at low cost.

Since the beginning of 1995 nearly all models for the European market are equipped with OEM immobilizers. First statistical analysis of insurance companies in Germany [1] confirm the tremendous success of these systems.Thefts of vehicles with electronic immobilizers decreased to about one tenth compared to vehicles without immobilizer.However criminal organizations have the means and the resources to develop high sophisticated equipment to overcome existing systems. Constant improvement of the security architecture is necessary to be one step ahead.This article describes the different security levels of key-based immobilizers.......