Security Enhancement in Mission-critical Free-space Optical Communication using AES-128 Encryption Algorithm

The Free Space Optical Communication (FSOC) technology has gained widespread popularity due to its multitude of advantages. FSOC offers enhanced security due to its narrow beam, Line-of-Sight (LoS) nature, and resistance to Electromagnetic Interference (EMI). However, ensuring data confidentiality in case of interception is critical. This work demonstrates data encryption using the Advanced Encryption Standard-128 (AES-128) to secure FSOC links. An encrypted optical signal was transmitted over a 2 km link and successfully decrypted at the receiver, ensuring that intercepted data remains unintelligible without the decryption key. This approach enhances FSOC’s reliability for secure transmission of sensitive or confidential information.