A Novel and Efficient 3D Multiple Images Encryption Scheme Based on Chaotic Systems and Swapping Operations

Single image encryption schemes are not efficient enough when a bunch of images is to be encrypted in some real-world setting. To overcome this problem, an efficient and secured multiple images encryption scheme is proposed in this study using two chaotic maps and simple row and column swapping operations in a 3D image space. The N input images are piled to make a 3D image. To confuse the given pixel data, two images are chosen randomly from this pile. The randomly chosen two rows from the two randomly chosen images are swapped with each other. In the same way, two randomly chosen columns are swapped with each other. The operation of randomly chosen two images, two rows, and two columns have been iterated an arbitrary number of times to throw the confusion effects in the pixels data. Intertwining Logistic Map (ILM) and Improved Piecewise Linear Chaotic Map (MPWLCM) have been used to get the four streams of random numbers. The three streams of the former map have been used to create the confusion effects, whereas the fourth stream of random numbers given by the latter map has been used for the diffusion effects. SHA-256 hash codes have been used to throw the plaintext sensitivity in the proposed cipher. Besides, a 256-bit user key has been employed to increase the key space. Both the simulation and the exhaustive security analyses carried out at the end vividly prove the security, resistance to the varied attacks, and the real-world applicability of the proposed cipher.