High bit rate secure FSO system utilizing Hill coding

Abstract To the best of our knowledge, this study is the first to build a secure free space optical communication system with a high bit rate of 80 Gb/s wavelength division multiplexing using a Hill coding cipher. The signal message was encrypted by applying an algorithm secure coding. According to the obtained results, in the event of favorable weather (fog), the link distance was about 4.4 km. The link distance was degraded in the bad weather (dust) to become 1.4. Furthermore, the suggested system has a communication merit (bitrate product repeater distance) of roughly 352 Gb/s km in fog conditions and 112 Gb/s km in dust conditions. This is regarded as the highest communication merit when compared to prior attempts and investigations. The effectiveness of the proposed encryption cipher has also been evaluated by a revision of various security studies, key space, correlations, histogram analyses, and results comparison with other alternative approaches. When compared to earlier studies and researches, this is thought to have the best communication merit. In addition, According to the outcomes, integrating cryptographic encryption and decryption methods into FSO systems maintained data security and offered resistance to eavesdropping assaults.