Simulation of a secure optical communication system using different optical modulation schemes coupled with Rivest-Shamir-Adleman algorithm

With the rise in the number of users in Radio Frequency (RF) communication systems, spectrum congestion is becoming a significant problem. So, there is an urgent need for an alternate and reliable system. Free Space Optical Communication (FSOC) comes to the rescue in such scenarios. Our main objective is to develop file encryption and encoding software using the Rivest-Shamir-Adleman (RSA) algorithm and optical modulation techniques, which we can use in an FSOC system. The reverse process, i.e., decoding and decryption logic in Python, is also done. We have implemented On-Off-Keying Non-Return-to-Zero-Inverted Modulation, On-Off-Keying Return-to-Zero Modulation, Pulse Position Modulation, Differential Pulse Interval Modulation and Dual-Header Pulse Interval Modulation schemes coupled with the RSA algorithm. The correctness of our Python codes is verified using a simple proof-of-concept model. We have also investigated the security of our proposed scheme.