Fast physical random bit generation using a millimeter-wave white noise source.

Area of Science:

• Optoelectronics
• Information Security
• Signal Processing

Background:

• Optical feedback can induce chaos in Fabry-Perot laser diodes (FP-LDs).
• Broadband millimeter-wave (MMW) signals are crucial for high-speed data transmission and secure communication.
• Physical random bit generation (PRBG) requires high-entropy, unpredictable signal sources.

Purpose of the Study:

• To demonstrate a novel method for generating broadband MMW white noise.
• To utilize this MMW signal for high-speed physical random bit generation.
• To investigate the chaotic dynamics of FP-LDs under optical feedback for signal generation.

Main Methods:

• Inducing chaos in two external-cavity feedback FP-LDs to broaden their optical spectra.
• Heterodyne beating of the broadened chaotic signals and photodetection to generate MMW white noise.
• Employing a simple least significant bits (LSBs) retaining method for random bit extraction from the MMW signal.

Main Results:

• Achieved a high-dimensional broadband chaos with MMW white noise characteristics (3-dB bandwidth > 50 GHz, no time-delay signature).
• Successfully generated physical random bits at a rate of 640 Gb/s.
• Demonstrated the effectiveness of the LSBs retaining method for PRBG using the MMW entropy source.

Conclusions:

• The proposed method effectively generates broadband MMW white noise from chaotic FP-LDs.
• This approach offers a viable solution for high-speed physical random bit generation.
• The simplicity of the LSBs retaining method makes it practical for real-world applications.