170,764 research outputs found
Characteristics of WAP traffic
This paper considers the characteristics of Wireless Application Protocol (WAP) traffic. We start by constructing a WAP traffic model by analysing the behaviour of users accessing public WAP sites via a monitoring system. A wide range of different traffic scenarios were considered, but most of these scenarios resolve to one of two basic types. The paper then uses this traffic model to consider the effects of large quantities of WAP traffic on the core network. One traffic characteristic which is of particular interest in network dimensioning is the degree of self-similarity, so the paper looks at the characteristics of aggregated traffic with WAP, Web and packet speech components to estimate its self-similarity. The results indicate that, while WAP traffic alone does not exhibit a significant degree of self-similarity, a combined load from various traffic sources retains almost the same degree of self-similarity as the most self-similar individual source
Usable Security: Why Do We Need It? How Do We Get It?
Security experts frequently refer to people as âthe weakest link in the chainâ of system
security. Famed hacker Kevin Mitnick revealed that he hardly ever cracked a password,
because it âwas easier to dupe people into revealing itâ by employing a range of social
engineering techniques. Often, such failures are attributed to usersâ carelessness and
ignorance. However, more enlightened researchers have pointed out that current security
tools are simply too complex for many users, and they have made efforts to improve
user interfaces to security tools. In this chapter, we aim to broaden the current perspective,
focusing on the usability of security tools (or products) and the process of designing
secure systems for the real-world context (the panorama) in which they have to operate.
Here we demonstrate how current human factors knowledge and user-centered design
principles can help security designers produce security solutions that are effective in practice
Stakeholder involvement, motivation, responsibility, communication: How to design usable security in e-Science
e-Science projects face a difficult challenge in providing access to valuable computational resources, data and software to large communities of distributed users. Oil the one hand, the raison d'etre of the projects is to encourage members of their research communities to use the resources provided. Oil the other hand, the threats to these resources from online attacks require robust and effective Security to mitigate the risks faced. This raises two issues: ensuring that (I) the security mechanisms put in place are usable by the different users of the system, and (2) the security of the overall system satisfies the security needs of all its different stakeholders. A failure to address either of these issues call seriously jeopardise the success of e-Science projects.The aim of this paper is to firstly provide a detailed understanding of how these challenges call present themselves in practice in the development of e-Science applications. Secondly, this paper examines the steps that projects can undertake to ensure that security requirements are correctly identified, and security measures are usable by the intended research community. The research presented in this paper is based Oil four case studies of c-Science projects. Security design traditionally uses expert analysis of risks to the technology and deploys appropriate countermeasures to deal with them. However, these case studies highlight the importance of involving all stakeholders in the process of identifying security needs and designing secure and usable systems.For each case study, transcripts of the security analysis and design sessions were analysed to gain insight into the issues and factors that surround the design of usable security. The analysis concludes with a model explaining the relationships between the most important factors identified. This includes a detailed examination of the roles of responsibility, motivation and communication of stakeholders in the ongoing process of designing usable secure socio-technical systems such as e-Science. (C) 2007 Elsevier Ltd. All rights reserved
Lepton Family Symmetry and Neutrino Mass Matrix
The standard model of leptons is extended to accommodate a discrete Z_3 X Z_2
family symmetry. After rotating the charged-lepton mass matrix to its diagonal
form, the neutrino mass matrix reveals itself as very suitable for explaining
atmospheric and solar neutrino oscillation data. A generic requirement of this
approach is the appearance of three Higgs doublets at the electroweak scale,
with observable flavor violating decays.Comment: 9 pages, including 1 figur
A Class of Coupled KdV systems and Their Bi-Hamiltonian Formulations
A Hamiltonian pair with arbitrary constants is proposed and thus a sort of
hereditary operators is resulted. All the corresponding systems of evolution
equations possess local bi-Hamiltonian formulation and a special choice of the
systems leads to the KdV hierarchy. Illustrative examples are given.Comment: 8 pages, late
Degenerate Metric Phase Boundaries
The structure of boundaries between degenerate and nondegenerate solutions of
Ashtekar's canonical reformulation of Einstein's equations is studied. Several
examples are given of such "phase boundaries" in which the metric is degenerate
on one side of a null hypersurface and non-degenerate on the other side. These
include portions of flat space, Schwarzschild, and plane wave solutions joined
to degenerate regions. In the last case, the wave collides with a planar phase
boundary and continues on with the same curvature but degenerate triad, while
the phase boundary continues in the opposite direction. We conjecture that
degenerate phase boundaries are always null.Comment: 16 pages, 2 figures; erratum included in separate file: errors in
section 4, degenerate phase boundary is null without imposing field equation
Integrating security and usability into the requirements and design process
According to Ross Anderson, 'Many systems fail because their designers protect the wrong things or protect the right things in the wrong way'. Surveys also show that security incidents in industry are rising, which highlights the difficulty of designing good security. Some recent approaches have targeted security from the technological perspective, others from the humanâcomputer interaction angle, offering better User Interfaces (UIs) for improved usability of security mechanisms. However, usability issues also extend beyond the user interface and should be considered during system requirements and design. In this paper, we describe Appropriate and Effective Guidance for Information Security (AEGIS), a methodology for the development of secure and usable systems. AEGIS defines a development process and a UML meta-model of the definition and the reasoning over the system's assets. AEGIS has been applied to case studies in the area of Grid computing and we report on one of these
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