Secure and Robust Optical Multi-Stage Medical Image Cryptosystem

Abstract

Due to the rapid growth of telemedicine and healthcare services, color medical image security applications have been expanded precipitously. In this paper, an asymmetric PTFrFT (Phase Truncated Fractional Fourier Transform)-based color medical image cryptosystem is suggested. Two different phases in the fractional Fourier and output planes are provided as deciphering keys. Accordingly, the ciphering keys will not be employed for the deciphering procedure. Thus, the introduced PTFrFT algorithm comprises asymmetric ciphering and deciphering processes in contrast to the traditional optical symmetric OSH (Optical Scanning Holography) and DRPE (Double Random Phase Encoding) algorithms. One of the principal impacts of the introduced asymmetric cryptosystem is that it eliminates the onedimensionality aspects of the related symmetric cryptosystems due to its remarkable feature of phase nonlinear truncation components. More comparisons on various color medical images are examined and analyzed to substantiate the cryptosystem efficacy. The achieved experimental outcomes ensure that the introduced cryptosystem is robust and secure. It has terrific cryptography performance compared to conventional cryptography algorithms, even in the presence of noise and severe channel attacks.

Novel competitive fractional chaotic circuits interaction networks with hierarchical structure and encryption application

“…• Entropy analysis Information entropy serves as a quantitative measure that captures the unpredictability and randomness within an image's pixel distribution. It's a fundamental metric in assessing the strength of encryption algorithms, where higher entropy values indicate a greater level of randomness and, by extension, a more secure encryption [65]. For grayscale images, the theoretical maximum entropy is 8 bits, which corresponds to a completely random distribution of pixel values where each gray level is equally likely.…”

“…To underscore the relevance of our proposed method, we conducted a comprehensive comparative analysis against established traditional chaotic encryption techniques in the literature [60,[62][63][64][65]. As shown in table 10, our comparison evaluation focused on the main key metrics critical to the effectiveness and robustness of encryption methods: computational complexity (time in seconds), correlation coefficient, and entropy.…”