2,194 research outputs found
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
Concept of Cryptographic Operations Based on Code Division Multiple Access
It is a given that numerous users connect to a single satellite transponder on a daily basis in order to communicate while discussing any satellite-based technology. As a result, they must all share the resources that are available without compromising the privacy of one another. Thus, the multiple access strategy is employed to achieve this. This paper focuses on code division multiple access, which does not require time slots or frequency slots to be shared across numerous users. The primary source of communication problems is multipath fading; and if the signal undergoes any multipath fading, then the total signal may be distorted. This work presents improved correlation features of the current Walsh code through one simple yet powerful algorithm. Here, a simulation-based method is used to evaluate performance. Utilizing power delay profiles in several mobile radio propagation channels, measurement-based channel models for indoor, outdoor, suburban, and urban environments are derived. The number of taps and tap gains are then estimated using statistics on the path loss characteristics. Since the source, output is known it is compared with a delayed version of the decision device output to obtain an empirical basis for the error rate. The suggested code’s performance is then compared to a few existing orthogonal and semi- orthogonal codes using a variety of performance criteria, and the conclusion is that this proposal is superior
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