Image encryption based on diffusion process and multiple chaotic maps

In the modern world, security is a prime important issue and encryption is one of the preeminent way to ensure security. There are many image encryption schemes. Each one of them has its own strength and weakness. This project presents a novel algorithm for the image encryption and decryption scheme. The project provides a secured image encryption technique using multiple chaotic based circular mapping. In this, first, a pair of sub keys is given by using chaotic logistic maps. Second, the image is encrypted using logistic map sub key and its transformation leads to diffusion process. Third, sub keys are generated by four different chaotic maps. Based on the initial conditions, each map may produce various random numbers from various orbits of the maps. Among those random numbers, a particular number are selected as a key for the encryption algorithm. Based on the key, a binary sequence is generated to manage the encryption algorithm. The input image of 2-D is transformed into a 1-D array by using raster scanning. It is then divided into various sub blocks. Then the position permutation is applied to each binary matrix based on multiple chaotic maps. Finally the receiver uses the same sub keys to decrypt the encrypted images. Also using the same encryption and decryption algorithm video is encrypted and decrypted. Finally shown that video encryption and decryption takes more time. Histogram analysis, correlation analysis are also done and found that there is no statistical similarity between original and encrypted image. Peak Signal to Noise ratio is also calculated and found that the encrypted image is of higher quality.