A Novel and Fast Encryption System Based on Improved Josephus Scrambling and Chaotic Mapping

Area of Science:

• Computer Science
• Cryptography
• Image Processing

Background:

• Existing permutation algorithms like the traditional Josephus ring permutation (TJRP) suffer from weak confusion and high time complexity.
• There is a need for more efficient and secure permutation algorithms for cryptographic applications.

Purpose of the Study:

• To develop an improved Josephus ring-based permutation (IJRBP) algorithm.
• To design a novel image encryption algorithm utilizing the IJRBP and a chaotic system.

Main Methods:

• The IJRBP algorithm replaces the remove operation with position exchange and uses random permutation steps for enhanced scrambling.
• A new encryption algorithm generates a diffusion matrix using a plaintext feature parameter and a chaotic system's random sequence.

Main Results:

• The IJRBP algorithm demonstrates superior scrambling effect and higher permutation efficiency compared to existing methods.
• The proposed image cryptosystem exhibits high sensitivity to plaintext changes, producing significantly different encrypted images.
• The system shows robustness against chosen-plaintext attacks (CPAs), noise attacks, and data loss.

Conclusions:

• The developed IJRBP algorithm addresses the limitations of traditional permutation methods.
• The novel image cryptosystem offers excellent encryption efficiency and strong resistance to common attacks, making it suitable for secure image transmission.