scholarly journals User Access Control and Authentication System for VoIP Service in Mobile Communication Environments

2014 ◽  
Vol 10 (2) ◽  
pp. 865869 ◽  
Author(s):  
Ho-Kyung Yang ◽  
Jeong-Kyung Moon ◽  
Cheol-Rim Choi ◽  
Hwang-Bin Ryou
2021 ◽  
Author(s):  
Roland M. C. Yuen

In this thesis, an optical fiber based radio access architecture that simultaneously provides services of the wireless local area network (WLAN) and the third generation (3G) mobile communication system is investigated. The sub-carrier multiplexed (SCM) technique of the fiber optic system is considered. The SCM architecture does not require frequency conversion and plays an important role enabling the WLAN to complement the cellular mobile communication systems so that the user can have both services as needed. In the SCM architecture, the two mediums that signals propagate are the air interface and the radio over fiber (ROF) link. In the air interface, the signal experience path loss and multipath fading that have effect on the system performance. The ROF link introduces nonlinear distortions and optical noise. The uplink and downlink analysis are performed in this thesis considering all the impairments from the air interface and the ROF link. Thereafter, numerical results are generated for both the uplink and downlink to illustrate the performance of the SCM architecture. The analysis identifies the interdependent relationship of the WLAN and the WCDMA system. The numerical results graphically illustrate such interdependent relationship. In the downlink, a 5 km ROF link operating at optimal power can support a WCDMA system with 1 km radius of coverage that has 26 dB of signal to distortion and noise ratio (SDNR); and a WLAN system with 400 m radius of coverage that has 27 dB of SDNR. The throughput of IEEE 802.11 WLAN depends on the medium access control. Hence, the medium access control is investigated and the throughput expression is modified to adapt to the SCM architecture where signals travel extra distance in a fiber.


2021 ◽  
Author(s):  
László Viktor Jánoky ◽  
Péter Ekler ◽  
János Levendovszky

JSON Web Tokens (JWT) provide a scalable, distributed way of user access control for modern web-based systems. The main advantage of the scheme is that the tokens are valid by themselves – through the use of digital signing – also imply its greatest weakness. Once issued, there is no trivial way to revoke a JWT token. In our work, we present a novel approach for this revocation problem, overcoming some of the problems of currently used solutions. To compare our solution to the established solutions, we also introduce the mathematical framework of comparison, which we ultimately test using real-world measurements.


Author(s):  
Saadia Kedjar ◽  
Abdelkamel Tari ◽  
Peter Bertok

With the advancement of web services technology, security has become an increasingly important issue. Various security standards have been developed to secure web services at the transport and message level, but application level has received less attention. The security solutions at the application level focus on access control which cannot alone ensure the confidentiality and integrity of information. The solution proposed in this paper consists on a hybrid model that combines access control (AC) and information flow control (IFC). The AC mechanism uses the concept of roles and attributes to control user access to web services' methods. The IFC mechanism uses labels to control how the roles access to the system's objects and verify the information flows between them to ensure the information confidentiality and integrity. This manuscript describes the model, gives the demonstration of the IFC model safety, presents the modeling and implementation of the model and a case study.


2012 ◽  
Vol 10 (3) ◽  
pp. 272-283 ◽  
Author(s):  
Haodong Wang ◽  
Qun Li

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