Novel structures of chaos-based parallel multiple image encryption and FPGA implementation

Area of Science:

• Cryptography
• Image Processing
• Computer Science

Background:

• Massive image data generation necessitates efficient and confidential encryption methods.
• Chaos-based image encryption offers effective data correlation reduction and confidentiality.
• Existing multiple image encryption algorithms often require same-sized images and simultaneous decryption, leading to inefficiencies.

Purpose of the Study:

• To propose novel chaos-based multiple image encryption structures that address limitations of current algorithms.
• To enable encryption and decryption of image cohorts with varying sizes and bit depths.
• To allow separate decryption of selected ciphertext images from a cohort, improving efficiency.

Main Methods:

• Developed three novel structures for chaos-based multiple image encryption integrating permutation, substitution, and diffusion processes in different orders.
• Employed a perturbed chaotic map and a linear-feedback shift register to generate session keys with image-content dependency.
• Utilized session keys for enhanced security through image-content dependency.

Main Results:

• Proposed cryptosystems successfully handle image cohorts with different sizes and bit representations.
• Individual ciphertext images can be decrypted separately, saving time and energy.
• Statistical analysis (NIST randomness test, entropy, histogram, correlation) and security analysis (key space, sensitivity) confirm effectiveness.
• Hardware implementation on FPGA demonstrated high throughput and efficiency.

Conclusions:

• The proposed chaos-based multiple image encryption structures offer significant improvements in flexibility, security, and efficiency over existing methods.
• These novel approaches are suitable for practical applications requiring high-speed and confidential processing of diverse image data.
• The findings pave the way for more robust and adaptable image encryption solutions in various domains.