Comments on “An image encryption scheme with a pseudorandom permutation based on chaotic maps”

Recently, Yoon et al. presented an image encryption scheme using a pseudorandom permutation based on chaotic maps (Commu. Nonlinear. Sci. Numer. Simut, 2010). In this paper, we exploit Yoon´s paper and point out some flaws related to its encryption and decryption algorithms. Furthermore, we suggest an improved scheme by modifying the encryption and decryption architectures of Yoon´s scheme. The experimental results show the new cryptosystem is robust and secure.