雷达导航避碰模糊识别

在多目标雷达导航避碰过程中,识别目标船相 对于本船可能发生碰撞的危险程度是驾驶员十分重要的工作,通常是由驾驶员根据经验作出 人为的识别或判断,本文运用模糊数学综合评判理论于船舶雷达导航避碰技术中,综合分析目 标相对于本船的方位,距离,最近碰撞点和最近碰撞时间参数,将目标碰撞危险程度这一模糊 概念加以数量化,最终提出一种新的目标碰撞危险度综合评判数学模型.  

一种基于ebXML的CPA自动生成模型与算法

讨论如何自动达成CPA，首先对产生CPA的基础文件(Collaboration-Protocol Profile,CPP)的文档结构进行分析，在此基础上提出一种CPA自动生成模型，并提出相应的CPA自动生成算法，从而为电子商务系统自动协作关系的建立提供一种实现方法。  

A hybrid fuzzy MCDM approach for evaluating website quality of professional accounting firms

Due to the popularity of internet, the CPAs can develop websites that properly deliver professional information and represent their firms. Effective use of CPA firm websites can increase communication with existing clients and attract potential clients. This study aims to build a hybrid approach that combines the fuzzy analytic network process (FANP) and fuzzy VlseKriterijumska Optimizacija I Kompromisno Resenje (FVIKOR) for evaluating website quality of the top-four CPA firms in Taiwan and provide worthwhile recommendations for enhancing website design and content. The results show that CPA firms included in this study do not utilize the Internet to its full potential and need to improve their websites. Deloitte has the best overall performance, follow by PricewaterhouseCoopers, Ernst & Young, and KPMG. Additionally, the top-five evaluation criteria in order of importance are richness, understandability, assurance, relevance, and reliability. Therefore, the findings of this study can help CPAs identify the strengths and weaknesses of their own websites and in comparison with those of their competitors, and then make resource allocation decisions about how to improve the status quo and achieve ideal websites.  

基于数据加密标准掩码的功耗分析方法

针对典型数据加密标准( DES)掩码实现的安全性问题，提出一种对其进行密钥破解的相关性功耗分析方法。结合DES运算后两轮，选择密码运算过程中间值中的分散位作为目标函数，利用汉明重量模型猜测第16轮运算的轮密钥，并计算功耗和中间值数据的汉明重量之间的相关性，根据相关性大小进行排序，从而破解掩码DES算法的密钥。实验结果表明，该方法取得了较好的效果，可成功破解掩码型DES算法的64位密钥。  

针对AES密码芯片的CPA攻击点选择研究

为解决AES密码芯片的相关性能量攻击(CPA)的攻击点选择问题,提出了一种CPA攻击点的选择方法,搭建了验证CPA攻击点有效性的仿真平台,并针对AES密码芯片进行了选择分析和验证实验。针对AES密码芯片提出了两种CPA攻击点选择——异或(XOR)操作攻击点和S盒(Sbox)操作攻击点。验证结果表明,两种选择都有效,其中后者的效果更好。  

针对AES密码芯片的CPA攻击

为证明未加抗功耗分析措施的AES密码芯片容易受到相关性功耗分析威胁的事实,提出了针对AES密码芯片的相关性功耗分析(CPA)方法,并进行了CPA功耗分析攻击实验.通过提取AES密码算法硬件结构中的关键寄存器信息,利用适当的功耗模型将这些信息转换为模拟瞬时功耗信息,并与采用实际测量装置测量的功耗信息进行相关性分析实验.实验成功破解了AES密码芯片中的最高8比特密钥值.实验结果表明了未加防御措施的AES密码芯片面临CPA攻击时的脆弱性.  

DES密码相关性功率分析中最小样本量计算

样本量是可以衡量设备抵 CPA攻击的重要指标,因此建立一种计算样本量的模型是很重要的.选择用统计学的方法通过计算样本量测定硬件的防护效果,这就可以让设计者在设计过程中通过计算了解设备抵御CPA的能力,还可以很容易地比较不同的防护方法,避免了由于产品不能有效抵 CPA攻击而进行的代价高昂的重复设计.  

Ciphertext verification security of symmetric encryption schemes

This paper formally discusses the security problem caused by the ciphertext verification,presenting a new security notion named IND-CVA(indistinguishability under ciphertext verification attacks) to characterize the privacy of encryption schemes in this situation. Allowing the adversary to access to both encryption oracle and ciphertext verification oracle,the new notion IND-CVA is slightly stronger than IND-CPA(indistinguishability under chosen-plaintext attacks) but much weaker than IND-CCA(indistinguisha...  

基于Oracle模型的可认证加密协议安全性分析

密码算法的安全定义研究以及定义间的深入理解已经成为现代密码学的主要研究领域.然而,当前多数可认证加密方案缺乏必要的安全性分析,为了分析协议安全性,在IND-CPA概念基础上,对加密与MAC组合与先MAC后加密两种对称式的可认证加密协议予以分析,并分别用Oracle机方法给出了IND-CPA攻击下的安全性证明.结果表明加密与MAC组合方式不能保证IND-CPA安全,但先MAC后加密方式则可实现IND-CPA安全.  

DR-PRE: dual receiver proxy re-encryption scheme

ABSTRACT

In this paper, we coin the notion of dual receiver proxy re-encryption. In dual receiver proxy re-encryption, the delegator’s ciphertext is re-encrypted using a single re-encryption key such that it can be decrypted by two-independent delegatees. To realize the dual receiver re-encryption, the traditional proxy re-encryption scheme requires two re-encryption keys to be generated, one for each delegatee and re-encryption should be done independently producing independent ciphertexts for each delegatee. This approach is computationally inefficient and requires larger bandwidth for ciphertext transmission. In the proposed dual receiver proxy re-encryption scheme based on bilinear mapping, only a single re-encryption key, only one re-encryption operation and only one ciphertext enables two delegatees to decrypt the common ciphertext independently. We prove the IND-CPA security of the proposed dual receiver proxy re-encryption scheme based on the DDH assumption. The proposed dual receiver proxy re-encryption scheme can be used in applications where a common ciphertext needs to be re-encrypted for two delegatees.