27,529 research outputs found
Grid Infrastructure for Domain Decomposition Methods in Computational ElectroMagnetics
The accurate and efficient solution of Maxwell's equation is the problem addressed by the scientific discipline called Computational ElectroMagnetics (CEM). Many macroscopic phenomena in a great number of fields are governed by this set of differential equations: electronic, geophysics, medical and biomedical technologies, virtual EM prototyping, besides the traditional antenna and propagation applications. Therefore, many efforts are focussed on the development of new and more efficient approach to solve Maxwell's equation. The interest in CEM applications is growing on. Several problems, hard to figure out few years ago, can now be easily addressed thanks to the reliability and flexibility of new technologies, together with the increased computational power. This technology evolution opens the possibility to address large and complex tasks. Many of these applications aim to simulate the electromagnetic behavior, for example in terms of input impedance and radiation pattern in antenna problems, or Radar Cross Section for scattering applications. Instead, problems, which solution requires high accuracy, need to implement full wave analysis techniques, e.g., virtual prototyping context, where the objective is to obtain reliable simulations in order to minimize measurement number, and as consequence their cost. Besides, other tasks require the analysis of complete structures (that include an high number of details) by directly simulating a CAD Model. This approach allows to relieve researcher of the burden of removing useless details, while maintaining the original complexity and taking into account all details. Unfortunately, this reduction implies: (a) high computational effort, due to the increased number of degrees of freedom, and (b) worsening of spectral properties of the linear system during complex analysis. The above considerations underline the needs to identify appropriate information technologies that ease solution achievement and fasten required elaborations. The authors analysis and expertise infer that Grid Computing techniques can be very useful to these purposes. Grids appear mainly in high performance computing environments. In this context, hundreds of off-the-shelf nodes are linked together and work in parallel to solve problems, that, previously, could be addressed sequentially or by using supercomputers. Grid Computing is a technique developed to elaborate enormous amounts of data and enables large-scale resource sharing to solve problem by exploiting distributed scenarios. The main advantage of Grid is due to parallel computing, indeed if a problem can be split in smaller tasks, that can be executed independently, its solution calculation fasten up considerably. To exploit this advantage, it is necessary to identify a technique able to split original electromagnetic task into a set of smaller subproblems. The Domain Decomposition (DD) technique, based on the block generation algorithm introduced in Matekovits et al. (2007) and Francavilla et al. (2011), perfectly addresses our requirements (see Section 3.4 for details). In this chapter, a Grid Computing infrastructure is presented. This architecture allows parallel block execution by distributing tasks to nodes that belong to the Grid. The set of nodes is composed by physical machines and virtualized ones. This feature enables great flexibility and increase available computational power. Furthermore, the presence of virtual nodes allows a full and efficient Grid usage, indeed the presented architecture can be used by different users that run different applications
Citizen Electronic Identities using TPM 2.0
Electronic Identification (eID) is becoming commonplace in several European
countries. eID is typically used to authenticate to government e-services, but
is also used for other services, such as public transit, e-banking, and
physical security access control. Typical eID tokens take the form of physical
smart cards, but successes in merging eID into phone operator SIM cards show
that eID tokens integrated into a personal device can offer better usability
compared to standalone tokens. At the same time, trusted hardware that enables
secure storage and isolated processing of sensitive data have become
commonplace both on PC platforms as well as mobile devices.
Some time ago, the Trusted Computing Group (TCG) released the version 2.0 of
the Trusted Platform Module (TPM) specification. We propose an eID architecture
based on the new, rich authorization model introduced in the TCGs TPM 2.0. The
goal of the design is to improve the overall security and usability compared to
traditional smart card-based solutions. We also provide, to the best our
knowledge, the first accessible description of the TPM 2.0 authorization model.Comment: This work is based on an earlier work: Citizen Electronic Identities
using TPM 2.0, to appear in the Proceedings of the 4th international workshop
on Trustworthy embedded devices, TrustED'14, November 3, 2014, Scottsdale,
Arizona, USA, http://dx.doi.org/10.1145/2666141.266614
A JSON Token-Based Authentication and Access Management Schema for Cloud SaaS Applications
Cloud computing is significantly reshaping the computing industry built
around core concepts such as virtualization, processing power, connectivity and
elasticity to store and share IT resources via a broad network. It has emerged
as the key technology that unleashes the potency of Big Data, Internet of
Things, Mobile and Web Applications, and other related technologies, but it
also comes with its challenges - such as governance, security, and privacy.
This paper is focused on the security and privacy challenges of cloud computing
with specific reference to user authentication and access management for cloud
SaaS applications. The suggested model uses a framework that harnesses the
stateless and secure nature of JWT for client authentication and session
management. Furthermore, authorized access to protected cloud SaaS resources
have been efficiently managed. Accordingly, a Policy Match Gate (PMG) component
and a Policy Activity Monitor (PAM) component have been introduced. In
addition, other subcomponents such as a Policy Validation Unit (PVU) and a
Policy Proxy DB (PPDB) have also been established for optimized service
delivery. A theoretical analysis of the proposed model portrays a system that
is secure, lightweight and highly scalable for improved cloud resource security
and management.Comment: 6 Page
A Survey on Wireless Security: Technical Challenges, Recent Advances and Future Trends
This paper examines the security vulnerabilities and threats imposed by the
inherent open nature of wireless communications and to devise efficient defense
mechanisms for improving the wireless network security. We first summarize the
security requirements of wireless networks, including their authenticity,
confidentiality, integrity and availability issues. Next, a comprehensive
overview of security attacks encountered in wireless networks is presented in
view of the network protocol architecture, where the potential security threats
are discussed at each protocol layer. We also provide a survey of the existing
security protocols and algorithms that are adopted in the existing wireless
network standards, such as the Bluetooth, Wi-Fi, WiMAX, and the long-term
evolution (LTE) systems. Then, we discuss the state-of-the-art in
physical-layer security, which is an emerging technique of securing the open
communications environment against eavesdropping attacks at the physical layer.
We also introduce the family of various jamming attacks and their
counter-measures, including the constant jammer, intermittent jammer, reactive
jammer, adaptive jammer and intelligent jammer. Additionally, we discuss the
integration of physical-layer security into existing authentication and
cryptography mechanisms for further securing wireless networks. Finally, some
technical challenges which remain unresolved at the time of writing are
summarized and the future trends in wireless security are discussed.Comment: 36 pages. Accepted to Appear in Proceedings of the IEEE, 201
Multidomain Network Based on Programmable Networks: Security Architecture
This paper proposes a generic security architecture
designed for a multidomain and multiservice network
based on programmable networks. The multiservice
network allows users of an IP network to run
programmable services using programmable nodes
located in the architecture of the network. The
programmable nodes execute codes to process active
packets, which can carry user data and control
information. The multiservice network model defined
here considers the more pragmatic trends in
programmable networks. In this scenario, new security
risks that do not appear in traditional IP networks become
visible. These new risks are as a result of the execution of
code in the programmable nodes and the processing of the
active packets. The proposed security architecture is based
on symmetric cryptography in the critical process,
combined with an efficient manner of distributing the
symmetric keys. Another important contribution has been
to scale the security architecture to a multidomain
scenario in a single and efficient way.Publicad
HiTrust: building cross-organizational trust relationship based on a hybrid negotiation tree
Small-world phenomena have been observed in existing peer-to-peer (P2P) networks which has proved useful in the design of P2P file-sharing systems. Most studies of constructing small world behaviours on P2P are based on the concept of clustering peer nodes into groups, communities, or clusters. However, managing additional multilayer topology increases maintenance overhead, especially in highly dynamic environments. In this paper, we present Social-like P2P systems (Social-P2Ps) for object discovery by self-managing P2P topology with human tactics in social networks. In Social-P2Ps, queries are routed intelligently even with limited cached knowledge and node connections. Unlike community-based P2P file-sharing systems, we do not intend to create and maintain peer groups or communities consciously. In contrast, each node connects to other peer nodes with the same interests spontaneously by the result of daily searches
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