Security-enhanced ultra-high-order QAM quantum noise stream cipher assisted by intensity and phase chaotic encryption

Area of Science:

• Optical Communications
• Quantum Cryptography
• Information Security

Background:

• Quantum noise stream cipher (QNSC) systems face security challenges.
• Quadrature Amplitude Modulation (QAM) is crucial for high-capacity optical transmission.
• Enhancing data security in high-speed communication is paramount.

Purpose of the Study:

• To propose a novel QAM quantum noise stream cipher (QNSC) scheme.
• To enhance security through ultra-high-order QAM and chaotic encryption.
• To improve the number of masked signals (NMS) and reduce detection failure probability (DFP).

Main Methods:

• Encryption of low-order QAM signals to ultra-high-order QAM using a pre-shared seed key (Y-00 protocol).
• Concealment of intensity and phase information via nonlinear chaotic sources.
• Utilizing open-loop chaotic synchronization for decryption.

Main Results:

• Numerical verification in 112 Gbit/s (16QAM) and 168 Gbit/s (64QAM) systems.
• Achieved transmission distances of 600 km and 150 km (7% HD-FEC), and 1000 km and 350 km (20% SD-FEC).
• Demonstrated significantly higher NMS and lower DFP compared to traditional QAM/QNSC systems.

Conclusions:

• The proposed ultra-high-order QAM QNSC scheme offers enhanced security.
• Chaotic encryption effectively conceals signal information, improving robustness.
• This scheme presents a promising strategy for secure high-speed optical communication.