Secure Authentication of WLAN Based on Elliptic Curve Cryptosystem

The security of wireless local area network (WLAN) becomes a bottleneck for its further applications. At present, many standard organizations and manufacturers of WLAN try to solve this problem. However, owing to the serious secure leak in IEEE802.11 standards, it is impossible to utterly solve the problem by simply adding some remedies. Based on the analysis on the security mechanism of WLAN and the latest techniques of WLAN security, a solution to WLAN security was presented. The solution makes preparation for the further combination of WLAN and Internet.     

Some remarks on the TKIP key mixing function of IEEE 802.11i

Temporal key integrity protocol (TKIP) is a sub-protocol of IEEE 802.11i. TKIP remedies some security flaws in wired equivalent privacy (WEP) protocol. TKIP adds four new algorithms to WEP: a message integrity code (MIC) called Michael, an initialization vector (IV) sequencing discipline, a key mixing function and a re-keying mechanism. The key mixing function, also called temporal key hash, de-correlates the IVs from weak keys. Some cryptographic properties of the substitution box (S-box) used in the key mixing function are investigated in this paper, such as regularity, avalanche effect, differ uniform and linear structure. Moen et al pointed out that there existed a temporal key recovery attack in TKIP key mixing function. In this paper a method is proposed to defend against the attack, and the resulting effect on performance is discussed.     

Filling the gap between voters and cryptography in e-voting

Cryptography is an important tool in the design and implementation of e-voting schemes since it can provide verifiability, which is not provided in the traditional voting. But in the real life, most voters can neither understand the profound theory of cryptography nor perform the complicated cryptographic computation. An e-voting system is presented in this paper to leverage the use of cryptography. It combines the advantages of voting scheme of Moran-Naor and voting scheme based on homomorphic encryption. It makes use of the cryptographic technique, but it hides the details of cryptographic computation from voters. Compared with voting scheme of Moran-Naor, the new system has three advantages: the ballots can be recovered when the voting machine breaks down, the costly cut-and-choose zero-knowledge proofs for shuffling votes made by the voting machine are avoided and the partial tally result in each voting machine can be kept secret. Foundation item: the National Natural Science Foundation of China (No. 60673076) and the National High Technology Research and Development Program (863) of China (No. 2008AA01Z403)     

"光化学烟雾"与汽车

氮氧化物主要是指NO、NO_2。NO、NO_2都是对人体有害的气体。氮氧化物(NO_x)和碳氢化合物(HC)在大气环境中受强烈太阳光紫外线照射后,产生一种复杂的光化学反应,生成一种新的二次污染物——光化学烟雾,在这种复杂的光化学反应过程中,主要生成光化学氧     

How to Play E-Lottery Games via Voting

Introduction Lotteryisapopulargameintherealworld.Howtoplayalotteryincyberspacehasreceived muchattention.E-lotteryisconvenientsinceplay-erscanpurchasethetickets,andobservethegen-erationoftheluckynumberovertheInternet.Manymethodstoprovidee-lotteryservicehave beenproposedintheliteratureinRefs.[1-6].The mainideaistousedelayingfunctionorweaklyse-cretbitcommitment(WSBC)tokeepthewinning numbersecretbeforethescheduledclosingtime.Inmoste-lotteryschemesaplayerpresentsaseed numberinhisticket.Thelucky…     

基于绝对编码器的角度测量装置的设计与实现

论文介绍了一种串行输出的绝对编码器的工作原理,重点描述了该编码器构成的轴向角度测量装置的组成和实现方法。结果表明此测角装置设计简单、性能可靠、测量准确。