Faculty of Accounting and Informatics

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Estimating effect of total specific atmospheric attenuation on performance of FSO communication link in South Africa
(Engineering and Technology Publishing, 2022) Maswikaneng, Solly P.; Adebusola, Samuel O.; Owolawi, Pius A.; Ojo, Sunday O.
In comparison with Radio Frequency (RF), the Free Space Optical Communication (FSOC) provides higher bandwidth, free license operation, and less initial expenditure. However, its susceptibility to changes in atmospheric weather conditions. In this paper, the impact of irradiance fluctuation on FSO systems was estimated using Rytov theory for major cities in South Africa. The extent to which the refractive index structure parameter, propagation distance and link margin affect the optical signal power at the receiver is discussed and the different methods used in evaluating the atmospheric turbulence effect are investigated. In order to achieve the stated aim, meteorological data, altitude, visibility, and wind speed were obtained from the archive of South Africa Weather Services for a period of 3years (2016-2018) over seven locations which include Cape Town, Pretoria, Upington, Bloemfontein, Emalahleni, Polokwane, East London. Results show that Emalahleni was found to possess the poor visibility of 4.4 km because of foggy conditions due to the activities of miners and other environmental factors, followed by East London with average visibility of 4.8 km. From the analysis of link margin, it was shown that FSO link attenuation reduces at higher wavelengths and long link distances due to the effect of geometric and atmospheric losses. The results show that the rate of decrease in link margin is much higher in the inland regions as compared to the coastal regions; therefore, FSO systems are prone to outage during high rainfall and longer range of connections.
RSA and elliptic curve encryption system : a systematic literature review
(IGI Global, 2024-03-20) Ugbedeojo, Musa; Adebiyi, Marion O.; Aroba, Oluwasegun Julius; Adebiyi, Ayodele, Ariyo; International Journal of Information Security and Privacy
Almost every living species has a motive to communicate electronically with one another and preserve data for immediate or future use. These data are becoming too large to be maintained on personal storage devices. Technological innovation has cleared the path for vast, remote storage known as the cloud. This innovation is being provided as a service to people and organizations due to the high cost of investment and the high-tech skills needed for its maintenance. Despite the many benefits of cloud computing, data privacy, integrity, and access control are issues that require immediate attention. Many studies have been conducted in order to find solutions to these challenges. In this review, the authors look at the numerous methods that have been proposed to address these security challenges. The research revealed that elliptic curve cryptography and the advance encryption system (AES) were the techniques that were most frequently used to address security issues in the digital world.