Chaotic encryption scheme for physical layer security in twin-SSB system via phase ambiguity

Area of Science:

• Optical Communications
• Physical Layer Security
• Chaos Engineering

Background:

• Traditional encryption methods face challenges in high-speed optical networks.
• Need for robust physical layer security to prevent signal interception.

Purpose of the Study:

• To propose a novel physical layer encryption method for optical twin-SSB signals.
• To integrate digital chaos and phase ambiguity for enhanced security.
• To demonstrate secure transmission of a complex modulated signal.

Main Methods:

• Utilizing digital chaos via phase ambiguity in a twin-SSB signal single-photodiode detection system.
• Implementing bit-level XOR encryption and chaotic sequence generation.
• Synthesizing a multiple-sideband-superposed 64-ary quadrature amplitude modulation (MSBS-64QAM) signal from GS-QPSK and GS-16QAM components.

Main Results:

• Achieved stable transmission of encrypted MSBS-64QAM over 10-km standard single-mode fiber.
• Bit error rates (BER) met hard-decision forward error correction (HD-FEC) thresholds.
• Demonstrated a key space magnitude of 10^90, offering strong resistance to brute-force attacks.

Conclusions:

• The proposed digital chaos-based encryption method provides dual-security protection for optical signals.
• The scheme shows significant potential for short-reach, high-capacity secure communication systems.
• Successful integration of chaos theory into optical communication security is demonstrated.