Reusing the permutation matrix dynamically for efficient image cryptographic algorithm

In traditional type of chaotic image ciphers with the architecture of permutation-diffusion, one-dimensional chaotic map is always employed for generating key steam in the diffusion procedure. However, the workloads derived from the iteration-then-quantization of the key stream generation operations severely downgrade the overall encryption efficiency of such cryptosystems. In this paper, we demonstrate how to obtain the diffusion key stream from the permutation matrix, which is produced and preserved in the permutation phase. No extra chaotic iteration and quantization is required in the diffusion procedure, the operation efficiency is thus improved. A complete cryptosystem is built using Bake map for image permutation. Simulations and security analyses have been carried out and the results illustrate the superior security and high efficiency of the proposed scheme. (C) 2015 Elsevier B.V. All rights reserved.