A Secure and Robust Data Transmission for 2 × 2 MIMO-OFDM System Using Subcarrier Randomization with Elliptical Curve Cryptography

This research proposes a method that randomizes the subcarrier as a physical layer security (PLS) in the Multiple-Input Multiple-Output Orthogonal Frequency Division Multiplexing (MIMO-OFDM) communication system, aiming to secure information data. The research procedure incorporates the Elliptic Curve Cryptography (ECC) algorithm during subcarrier randomization, including processes such as public key generation, encryption, and decryption, and compares these with the Rivest Shamir-Adleman (RSA) method. The proposed method is validated through real-time laboratory experiments, yielding significant results. The RSA algorithm’s average time is 6.73 and 53.21 seconds, while the ECC algorithm requires only 0.71 and 1.21 seconds for security bits of 80 and 112, respectively. The performance of bit error rate (BER) versus signal-to-noise ratio (SNR) is 0.123 times 10 to the power of negative 3, demonstrating that the subcarrier randomization and reconstruction system is successfully implemented and working correctly to ensure security based on the MIMO-OFDM system.