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Beate Grawemeyer 《Interacting with computers》2011,23(3):256-267
Security policies are required that protect information from unauthorised access, and also respect challenges users face in creating, and particularly managing, increasing numbers of passwords. This paper investigates real password use in the context of daily life. It presents the results of an empirical study where participants completed a password diary over 7 days, followed by debrief interviews to gain further knowledge and understanding of user behaviour. The results reported relate to how many passwords are in use, the types of passwords participants created, the relationships between different passwords and to sensitive services, how participants retrieved their passwords and finally, the different strategies adopted by users in their management of passwords. The paper concludes by providing a high level set of password guidelines, along with suggestions for mechanisms to support creating, encoding, retrieving and executing multiple passwords. 相似文献
166.
RFID标签所有权转移协议研究 总被引:11,自引:0,他引:11
无线射频识别技术(RFID)是适用于普适计算环境的技术之一,它的应用正在变得随处可见.RFID安全与隐私问题是这些应用的基本需求之一,由于RFID标签的资源限制,传统的安全元素不能很好地应用到RFID标签中.因此,设计轻量级的安全机制非常重要.应用中,贴有标签的物品经常发生所有权的转移.这就需要保护原所有者与新所有者的... 相似文献
167.
针对涉密数据在多个域之间传输的安全需求,介绍一种新的涉密数据跨域传输机制。该机制基于一种新的跨域认证与密钥建立协议,借助各域内的监督服务器完成双向认证,并结合签密法建立新的文件传输密钥。安全分析证明,该机制能保证不同安全等级域之间涉密数据传输的安全性和隐密性,并能抵御多种安全攻击。 相似文献
168.
Recently, Yang et al. proposed an efficient user identification scheme with key distribution, in which it is possible for the user to anonymously log into a system and establish a secret key shared with the system. Mangipudi and Katti later demonstrated a Deniable-of-Service (DoS) attack on the Yang et al. scheme and then proposed an improvement to withstand such an attack. However, this paper demonstrates an identity disclosure attack to show that neither schemes’ claimed user anonymity requirement can be achieved. We further propose a novel user identification scheme with key distribution preserving user anonymity for distributed computer networks. The proposed scheme not only withstands the attacks mentioned above, but also achieves the following: (i) user anonymity, (ii) key distribution, (iii) mutual authentication, and (iv) key confirmation. The performance of our scheme is of greater efficiency than that of previously proposed schemes in terms of communication costs and computational complexities. 相似文献
169.
Secure authentication features of communication and electronic commerce protocols involve computationally expensive and memory intensive cryptographic operations that have the potential to be turned into denial-of-service (DoS) exploits. Recent proposals attempt to improve DoS resistance by implementing a trade-off between the resources required for the potential victim(s) with the resources used by a prospective attacker. Such improvements have been proposed for the Internet Key Exchange (IKE), the Just Fast Keying (JFK) key agreement protocol and the Secure Sockets Layer (SSL/TLS) protocol. In present article, we introduce probabilistic model checking as an efficient tool-assisted approach for systematically quantifying DoS security threats. We model a security protocol with a fixed network topology using probabilistic specifications for the protocol participants. We attach into the protocol model, a probabilistic attacker model which performs DoS related actions with assigned cost values. The costs for the protocol participants and the attacker reflect the level of some resource expenditure (memory, processing capacity or communication bandwidth) for the associated actions. From the developed model we obtain a Discrete Time Markov Chain (DTMC) via property preserving discrete-time semantics. The DTMC model is verified using the PRISM model checker that produces probabilistic estimates for the analyzed DoS threat. In this way, it is possible to evaluate the level of resource expenditure for the attacker, beyond which the likelihood of widespread attack is reduced and subsequently to compare alternative design considerations for optimal resistance to the analyzed DoS threat. Our approach is validated through the analysis of the Host Identity Protocol (HIP). The HIP base-exchange is seen as a cryptographic key-exchange protocol with special features related to DoS protection. We analyze a serious DoS threat, for which we provide probabilistic estimates, as well as results for the associated attacker and participants' costs. 相似文献
170.
提出了一种新的用于灵活图像认证的多重水印嵌入算法.不同于传统的块独立水印算法中每个图像块只嵌入一个水印信息,算法对每个图像块嵌入多重水印信息.提出了两个通用的图像块等级模型,形成图像块内部的等级结构,对每个图像块以及图像块内部的各等级子块进行独立的水印生成和嵌入.将图像特征值映射为混沌系统的初值,并将图像块的编号映射为混沌系统的迭代次数,经过混沌迭代生成图像块水印,再将水印信号替代图像块中选定像素点的最低有效位,完成水印的嵌入.实验结果表明,该算法可对图像进行多重认证,对篡改区域进行精确的检测与定位,并能选择不同的定位精度. 相似文献