Color image encryption strategy of Ro-FSO network systems based on CBC and Blowfish cipher

Abstract

The escalating demand for critical network functions has intensified the urgency of addressing security vulnerability in optical communication systems. This work builds a secure 64-channel scheme to study the execution of a hybrid Radio over Free Space Optics (RoFSO) communication system under variable conditions of weather using a Blowfish coding cipher. The system's targeted speed is 640 Gbps data transmission. Over an FSO communication link, the radio frequency (RF) signal parameters were set at 35 GHz (high band 5G) in optical form, with the receiver able to clearly receive data. According to the results, the maximum transmission range of 1.9 km was achievable with an amplifier in medium fog. However, when the transmission took place in hazy conditions, the maximum signal degradation, as indicated by the attenuation, measured 20.685 dB/km. The degree of protection offered is demonstrated by its large key space; resistance to brute-force, differential, and anti-differential attacks; reduced correlation between neighboring pixels; flattened histogram of the encoded original picture; and rising entropy for the scenarios examined. Based on the results, data security in FSO systems is preserved through the successful integration of cryptographic encryption and decryption techniques.