Optical compression and encryption system combining multiple measurement matrices with fractional Fourier transform.

Area of Science:

• Cryptography and Information Security
• Optical Engineering
• Signal Processing

Background:

• Optical cryptosystems combined with compressed sensing offer simultaneous image compression and encryption.
• Existing methods using a single measurement matrix are vulnerable to chosen plaintext attacks.
• The fractional Fourier transform (FrFT) domain is utilized for improved visual effects in decryption.

Purpose of the Study:

• To propose a robust optical cryptosystem resistant to chosen plaintext attacks.
• To enhance the security and effectiveness of combined compression and encryption.
• To improve the visual quality of wrongly decrypted images.

Main Methods:

• Adoption of multiple measurement matrices derived from a basic one via random row exchanging.
• Encoding the measurement matrices into the fractional Fourier transform (FrFT) domain.
• Incorporation of chaos-based pixel scrambling for nonlinearity.

Main Results:

• The proposed scheme effectively overcomes the vulnerability of single measurement matrix methods.
• Enhanced security against chosen plaintext attacks is demonstrated.
• The system shows high effectiveness in simultaneous compression and encryption.

Conclusions:

• The developed optical cryptosystem provides a robust and secure solution for image compression and encryption.
• The use of multiple measurement matrices and chaos-based scrambling significantly improves security.
• The scheme is effective and suitable for practical applications requiring secure image processing.