Digital Image Encryption based on Transformation and Henon Chaotic Substitution

This paper intends a fast and efficient cryptosystem based on confusion and Henon chaotic diffusion. The algorithm encrypts an image in two stages. In the first stage, the original images is transformed using Pseudo Hadamard transformation (PHT) along with substitution image. The key length used in the algorithm is 128 bits. These secrete key digits are used as initial conditions for Henon chaotic generator. A substitution box (S-box) is constructed using random sequences generated by chaotic generator. The cipher image from confusion stage is then subjected for diffusion using S-box. Based on the results obtained from differential and analytical tests, the proposed algorithm can withstand such security attacks compared to existing systems.