Design and performance analysis of a 40 Gbps secure FSO link using ElGamal encryption under dust storm conditions in Anbar, Iraq

Abstract This study describes the construction of a multichannel free-space optical (FSO) communication system with great efficiency and speed in delivering grayscale pictures. The system operates on the simultaneous transmission of four separate grayscale pictures, allowing for a data throughput rate of up to 40 Gbps (via 4 × 10 Gbps WDM channels) while maintaining advanced levels of protection for the sent data. Since dust is often the greatest challenge for FSO, we also looked at its effects using the Kim and Kruse models to obtain findings that correctly represent reality. These studies demonstrated that, particularly at low and medium dust levels, the Kruse model provides less signal attenuation than the Kim model. The maximum range in light dust was 1,010 m for the Kim model (8.12 dB/km) and 1,094 m for the Kruse model (6.94 dB/km). These distances decreased to 513 m for the Kim model (25.49 dB/km) and 665 m for the Kruse model (16.98 dB/km). In the worst weather conditions (heavy dust), the critical link range dropped to only 122 m for the Kim model (169.8 dB/km) compared to 155 m for the Kruse model (128.168 dB/km). While maintaining acceptable performance parameters like bit error rate (BER) and quality factor (Q-factor), the proposed encryption algorithm’s efficiency was verified through a comprehensive suite of security analyses.