Abstract: This paper proposes a novel confusion and diffusion algorithm for image encryption based on logistic map and cheat image. We choose the initial condition and control parameter of logistic map as the secret key. The cheat image selected from the most common images in public network, together with the chaotic matrices generated by logistic maps, is employed both in encryption and decryption processes to encrypt and recover the plain image. One cheat image can be used to encrypt a great number of plain images if the cheat image does not attract the attention of the attackers. The computer experiments such as statistical analysis, sensitivity analysis, differential attack analysis and cheat characteristic analysis, prove that the proposed image encryption algorithm is robust and secure enough to be used in practical communication.