Secured Medical Images - a Chaotic Pixel Scrambling Approach.

Area of Science:

• Cryptography
• Image Processing
• Medical Imaging

Background:

• Digital medical images, particularly DICOM, require robust encryption to protect sensitive patient data.
• Existing image encryption methods may lack sufficient security against sophisticated attacks.

Purpose of the Study:

• To propose a novel and secure cryptosystem for 16-bit monochrome DICOM images.
• To enhance the security and efficiency of image encryption using a new chaotic map.

Main Methods:

• Design of a new Enhanced Chaotic Economic Map (ECEM) with improved bifurcation and Lyapunov exponent properties.
• Generation of pixel permutation, masking, and swapping sequences using the ECEM.
• Integration of a substitution operation between permutation and diffusion stages.
• Comprehensive security analysis including histogram, key sensitivity, key space, NPCR, UACI, information entropy, and correlation coefficient.

Main Results:

• The ECEM demonstrates superior bifurcation behavior and positive Lyapunov exponents.
• The proposed algorithm exhibits a large key space, effectively resisting brute-force attacks.
• Security analyses confirm high NPCR and UACI values, indicating strong diffusion and confusion.
• Low correlation coefficients between adjacent pixels demonstrate effective scrambling.

Conclusions:

• The proposed DICOM image encryption algorithm provides enhanced security and robustness compared to existing methods.
• The novel ECEM contributes to a more secure and reliable cryptosystem for medical image data protection.
• The algorithm is well-suited to withstand various common and advanced cryptanalytic attacks.