内置安全散列算法的iButton存储器及其应用

本文介绍了一种符合国际标准SHA-1的安全数据存储器DS1961S,包括产品的主要性能、内部结构以及它所采用的安全散列算法(SHA-1)原理和计算方法。文中总结了DS1961S的一些成功应用及潜在的应用,值得广大设计人员参考和推广应用。     

预付费电能表应用技术探讨

本文从预付费电能表的分类及基本功能、检定测试、现场安装、用户使用等方面对预付费电能表的应用进行了全面探讨,提出了预付费电能表在实验室检测、现场安装以及用户使用方面的注意事项。本文对预付费表检定、安装、使用人员有一定参考意义。     

串行EEPROM DS2431的特性及其在智能ODN中的应用

文章介绍了美国Maxim公司的串行EEPROM DS2431芯片的特性及工作原理,提供了DS2431与单片机IAP15L2K61S2的1-Wire总线连接方法,并且简要阐述其在智能ODN中的应用。     

基于RTX51嵌入式操作系统的智能卡电能表的设计

介绍了一种基于RTX51嵌入式多任务实时操作系统的智能卡电能表,主要硬件结构包括MCU为STC12LEC5A60S2,单相电能计量芯片ADE7755,采用铁电存储器FM25C160存储相应数据。通过将ADE7755计量电能至存储器,并与用户可用电量比较,若是电量不足以支付,则声光报警提醒用户,通过智能卡接口完成智能卡电表的预付费功能。     

基于电力线载波通信的CPU卡预付费电能表的设计

将电力线载波通信技术与CPU卡技术相结合,设计了一款新型的预付费电能表。将CDMA多址技术运用于自动抄表系统中,将CPU卡应用于电能表预付费管理系统中,解决了“抄表难”和“收费难”的同时,也保证了系统的安全性。系统采用SoC芯片设计,具有很高的稳定性和实用性。     

基于RFID的单相电子式预付费电能表的设计

为了适应电能表高精度、低功耗、智能化的发展趋势,将射频识别技术应用到电子式预付费电能管理系统。介绍了系统的结构和工作流程,给出了主要电路模块的原理图,包括电能计量部分、射频接口部分等,并从低功耗和抗干扰等方面进行了可靠性设计。射频识别技术是未来电能表的一种重要的发展方向。     

DS1963S及其在SHA中的应用

在简要介绍了SHA算法 (一种数据加密算法 )的基础上 ,通过介绍1-Wire器件DS1963S的特性及工作原理 ,给出了DS1963S在SHA中的应用方法     

预付费电表的发展历程及技术热点

本文主要介绍了预付费电表在中国的成长历程,分析了采用预付费电表给电力公司和供电管理部门带来的变革,描述了中国使用的预付费电表所具备的主要功能,分析了和预付费电表相关的一些技术热点,对未来预付费电表的市场进行了预期。     

电能计量系统发展简史

基于互感器、电能表和二次接口等方面回顾了电能计量装置的发展历程和原理,对21世纪现代电能计量装置的发展趋势进行了展望,指出数字化、智能化、标准化、系统化和网络化是现代电能计量系统发展的必然趋势。另外,还介绍了几个新型互感器(Rogowski光电式电流互感器、法拉第磁光效应互感器和光学电压互感器),特殊功用的新型电能表(单相电子式复费率电能表和三相预付费电表)和常用电能计量芯片。     

国内卡式预付费电能表市场前景展望

预付费电能表应用市场正在异军突起,作为三金工程的重点发展领域,国家产业政策鼓励其大力发展。1995年,在国家计委、国家经贸委、电力部在沪召开的全国计划用电工作会议上决定,参照国外的先进做法,自1996年起在全国全面推行峰平谷分时电价制度,以提高电力的应用率,这将大大刺激预付费电能表市场的发展。     

基于信息纽扣的预付费电度表的设计

数字式预付费电度表目前主要采用IC卡,在性能方面存在一些不足。该设计所采用的智能卡是美国达拉斯半导体公司推出的一种智能化信息载体信息纽扣iButton。介绍利用信息纽扣组成预付费电度表的设计方法,重点描述信息纽扣的特点和使用方法,阐述相关的硬件和软件的设计方法。采用这种方案相对IC卡系统具有操作方便、稳定性高、便于携带、使用寿命长等特点。     

非接触式IC卡预付费煤气表的设计方法

全面阐述了一种用TEMIC公司的非接触式E5550IC卡和串行E2 PROM、串行时钟及AT89C2 0 51单片机所组成能分时计费的预付费煤气表的设计方法 ,对设计中的一些具体问题进行了讨论和探讨 ,并得到较好的应用效果。     

智能卡水表及其专用集成电路的设计与实现

本文介绍了一种新型智能卡水表。它较好地解决了普通IC卡表易受攻击和可靠性低的缺点。该表内部采用两块具有自主知识产权的专用集成电路LC47127和LC47128。还介绍了这种新型电表的性能特点与功能结构以及应用原理和方法。表明这是一种适合我国国情的替代传统水表的优选方案。     

A Fault Detection Scheme for the FPGA Implementation of SHA-1 and SHA-512 Round Computations

The Secure Hash Algorithm is the most popular hash function currently used in many security protocols such as SSL and IPSec. Like other cryptographic algorithms, the hardware implementation of hash functions is of great importance for high speed applications. Because of the iterative structure of hash functions, a single error in their hardware implementation could result in a large number of errors in the final hash value. In this paper, we propose a novel time-redundancy-based fault diagnostic scheme for the implementation of SHA-1 and SHA-512 round computations. This scheme can detect permanent as well as transient faults as opposed to the traditional time redundancy technique which is only capable of detecting transient errors. The proposed design does not impose significant timing overhead to the original implementation of SHA-1 and SHA-512 round computation. We have implemented the proposed design for SHA-1 and SHA-512 on Xilinx xc2p7 FPGA. It is shown that for the proposed fault detection SHA-1 and SHA-512 round computations, there are, respectively, 3% and 10% reduction in the throughput with 58% and 30% area overhead as compared to the original schemes. The fault simulation of the implementation shows that almost 100% fault coverage can be achieved using the proposed scheme for transient and permanent faults.     

一种在智能卡芯片中实现SHA-1算法的方法

SHA是由美国国家安全局(NSA)设计的安全杂凑算法.该算法主要应用在通讯完整性验证以及数字签名认证领域.以面积优化为目标,从系统设计入手到模块级设计,以具体设计为实例,在智能卡芯片中以较小的面积代价实现了SHA-1算法,对于类似的杂凑算法设计具有普遍的参考价值.     

Paying for energy the smart way

A new approach to prepayment schemes could make it easier for UK consumers to shop around for the best value gas and electricity. The proposed approach to smart prepayment uses the same building blocks as a traditional budget scheme. For each day of the week, the meter records the energy used in each half hour period and calculates average usage over a specified period which can be monthly, quarterly etc. The majority of consumers will fall into a small number of profiles, so matching the consumption pattern to one of a number of preprogrammed profiles downloaded from the vending system via the smart card or communications channel would take up less storage space. When the customer wants to top up their gas or electricity credit they visit a vending machine which uses the consumption data stored on their card to allocate a tariff and calculates how much energy to offer the consumer for their money. A multi-supplier machine could even compare the different tariffs available to a customer with a particular profile and offer the cheapest. Once the transaction is complete, the card is credited with the amount of energy purchased for downloading to the meter. The meter would be capable of interrupting the supply when credit has been used, although there would probably have to be an emergency credit facility-paid back at the next transaction-to provide a period of grace     

SHA-256算法的安全性分析

现有算法MD5、SHA-1等的相继破译,严重威胁到SHA-256、SAH-384等算法的安全性.本文介绍了SHA-256的算法逻辑及压缩函数的构造,探讨了生日攻击碰撞阈值和攻击步骤,分析了SHA-256在生日攻击下的安全性.通过对Chabaud-Joux攻击SHA-256的分析,找到了一个部分碰撞,其复杂度为,却无法找到SHA-256的一个整体碰撞.所以,在抵抗生日攻击和抵御现有差分攻击方面,SHA-256比MD5和SHA-1等具有更高的安全性.     

LTE系统密钥生成算法研究

介绍了单向散列函数特性和SHA-256算法原理.基于C语言实现SHA-256算法的程序设计,在Visual C++6.0环境下仿真测试结果,对该算法的单向散列函数特性进行了分析.对24组1 024 bit测试数据测试分析,结果表明,SHA-256算法具有理想的单向散列函数特性.     

Security of Internet of Things using RC4 and ECC Algorithms (Case Study: Smart Irrigation Systems)

Internet of Things (IoT) deploys a wide range of technologies including wireless sensor networks, machine-to-machine communication, robots, internet technologies, and smart devices. IoT is a novel phenomenon in the IT world wherein objects can transmit data, and interact through the internet or intranet networks. But the most important and crucial issue on the IoT is privacy and data security. The objective of this paper is to create a new encryption model for data storage servers in an IoT-based irrigation systems. Thus, a hybrid encryption algorithm based on Elliptic Curve Cryptography (ECC), RC4, and SHA-256 is proposed to protect sensitive data of IoT-based irrigation systems. The proposed model uses ECC to improve RC4. In RC4, XOR operation is performed using a key encrypted by ECC and shift-right, and then the resulting data are transformed to SHA-256 to ensure security. Simulation results indicate that encryption and decryption time in the proposed model are shorter than other models like XXTEA & ECC, XXTEA & RSA, ECC&3DES&SHA-256, RC4&3DES&SHA-256, AES&RC4&SHA-256, AES&3DES &SHA-256, RC4&AES&SHA-256, RC2&3DES&SHA-256, and ECC&RC2&SHA-256 with, 43.39%, 66.03%, 45.28%, 54.71%, 50.94%, 33.96%, 33.62%, 24.52%, and, 15.09% respectively.