A Robust Visually Secure Bit Plane Image Encryption Using Chaotic Map and SHA-512

With the introduction of the latest digital technologies, the protection of images from unauthorized use has become increasingly important, necessitating the development of robust image encryption techniques. This paper proposes a novel bit plane image encryption method that incorporates chaos theory and cryptographic hash functions. To ensure a high degree of security, the key for the three-dimensional Intertwining Logistic chaotic map is generated (initial conditions) using the SHA-512 hash algorithm. The chaotic map is then utilized to generate two random vectors and one random matrix, respectively. In order to shuffle the original bit plane structure, random vectors are used to scramble the pixel positions across the bit planes. A bitwise XOR operation is then performed on the shuffle bit planes with the third random matrix. To avoid the attention of potential hackers, a visually secured ciphertext image is generated by embedding the noise-like ciphertext within a host image. Several tests, such as histogram, correlation coefficient, key sensitivity, key space, entropy, Number of Pixel Change Rate (NPCR), and Unified Average Change Intensity (UACI), were performed on the proposed visually secured bit plane image encryption scheme. As a result of the extensive tests, one can conclude that the proposed scheme is robust and can withstand a wide range of possible cryptographic attacks.