A robust image encryption technique based on an improved fractional order chaotic map

This paper presents a novel color image encryption technique using a fractional chaotic map to enhance the security of color images transmitted over insecure channels. The fractional ordered chaotic map is designed to address the limitations inherent in traditional chaotic maps. The proposed fractional ordered chaotic map demonstrates a high Lyapunov exponent and exceptional sensitivity to initial conditions, as evidenced by time series analysis and sample entropy evaluations, indicating its robustness and unpredictability. A circuit-based approach is incorporated into the chaotic map for practical implementation and potential applications. Additionally, the chaotic map surpasses the thresholds established by the NIST SP 800-22 tests, confirming its superior performance in generating random sequences. The pixel shuffle operator disrupts neighborhood relationships between pixels, thereby enhancing the security by making it more challenging for attackers to discern patterns. The diffusion phase further complicates the encryption by modifying pixel values based on the values of adjacent pixels, effectively obscuring any correlations between the original and encrypted images. Experimental validation, including extensive analyses of histograms, entropy, and pixel correlation metrics, demonstrates the proposed scheme's efficacy. The results confirm that the encryption technique provides strong resistance against statistical attacks, ensuring the secure and reliable transmission of color images. This work represents a significant advancement in the field of image cryptography, combining the strengths of fractional order chaotic systems with pixel manipulation techniques.