Covert chaotic encryption scheme based on compressive sensing in a W-band RoF system.

Area of Science:

• Cybersecurity
• Optical Communications
• Signal Processing

Background:

• Multimedia data security is crucial.
• Existing encryption methods face challenges in high-capacity transmission.
• Compressive Sensing (CS) offers potential for efficient data handling.

Purpose of the Study:

• To propose a novel covert chaotic encryption (CCE) scheme.
• To integrate CCE with compressive sensing (CS) for enhanced security and efficiency.
• To evaluate the scheme's performance in a W-band radio-over-fiber (RoF) system.

Main Methods:

• Utilizing a six-dimensional hyper-chaotic D-system for sequence generation.
• Employing chaotic sequences for chaotic index sparse block (CISB), CS measurement matrix generation, variable-parameter iterative Arnold transformations, and dual-random LSB scrambling/embedding.
• Implementing the CCE-CS scheme within a 4 Gb/s W-band OFDM-RoF system.

Main Results:

• Achieved multi-domain, multi-dimensional, ultra-high-security encryption for image data.
• Demonstrated a bit error rate (BER) below the FEC threshold of 3.8×10⁻³ for input optical power (IOP) > 1 dBm.
• Obtained a mean structural similarity index (MSSIM) of 0.96 at 6 dBm IOP, indicating excellent reconstruction quality.
• Key space reached 10¹⁶⁰, ensuring robust resistance against attacks.
• Reduced transmission data volume by 75% compared to non-CS schemes.

Conclusions:

• The proposed CCE-CS scheme provides ultra-high security and efficiency for multimedia image encryption.
• The integration with W-band RoF systems shows significant potential for high-capacity, secure optical wireless communication.
• The scheme effectively balances security, data reduction, and transmission quality.