Highly secure non-orthogonal multiple access based on key accompanying transmission in training sequence

Area of Science:

• Optical Communications
• Information Security
• Signal Processing

Background:

• Non-orthogonal multiple access (NOMA) enables efficient spectrum utilization in optical networks.
• Secure data transmission is crucial for advanced communication systems.
• Existing encryption methods may face challenges in complex fiber optic networks.

Purpose of the Study:

• To propose a high-security chaotic encrypted power sparse coding division (CE-PSCD) scheme for 7-core fiber.
• To enhance data security and user fairness in NOMA-based systems.
• To demonstrate a novel encryption dimension for sparse codes.

Main Methods:

• Utilizing power multiplexing for parallel signal transmission.
• Implementing joint encryption via constellation mapping, carrier frequency, symbol scrambling, and sparse code scrambling.
• Hiding chaotic keys within training sequences (TS) for co-transmission with data.

Main Results:

• Experimental demonstration of a 70 Gb/s CE-PSCD signal transmission over 2 km of 7-core fiber.
• Achieved user fairness with only a 0.36 dB difference in encrypted sensitivity at equal power levels.
• Key space reached 10^134, with a bit error rate (BER) of ~0.5 for brute-force attacks and single-bit key errors.

Conclusions:

• The proposed CE-PSCD scheme offers high security and maintains user fairness.
• The encryption method shows no significant signal attenuation, validating its effectiveness.
• The novel approach provides a robust solution for secure optical communication.