Chaotic physical layer encryption scheme based on phase ambiguity for a DMT system.

Area of Science:

• Optical Communications
• Physical Layer Security
• Information Security

Background:

• Chaotic encryption is a key technology for physical layer security in optical communications.
• Constellation shifting (CS) is a common symbol-level encryption method but faces challenges with computational complexity and compatibility with other techniques.
• Existing methods struggle with integration with probabilistic shaping (PS) and blind equalization algorithms.

Purpose of the Study:

• To propose a novel symbol-level chaotic encryption scheme based on phase ambiguity (PA).
• To address the technical flaws of the conventional constellation shifting (CS) scheme.
• To enhance security and efficiency in optical communication systems.

Main Methods:

• Developed a new symbol-level encryption scheme using phase ambiguity (PA).
• Transformed chaotic sequences into phase rotation and complex conjugate keys.
• Simulated and experimentally verified the scheme in a discrete multi-tone (DMT) system with 64-quadrature amplitude modulation (QAM).

Main Results:

• The proposed PA scheme maintains the shaping gain from probabilistic shaping (PS).
• It effectively avoids error convergence issues with blind equalization algorithms.
• The PA scheme demonstrates significantly reduced computational complexity, requiring only 38% of the time compared to the CS scheme.

Conclusions:

• The novel phase ambiguity (PA) encryption scheme is a practical and superior alternative for physical layer security in optical communications.
• It offers enhanced efficiency and compatibility, overcoming limitations of the CS scheme.
• The PA scheme is well-suited for future secure optical communication systems.