Abstract
This paper presents an efficient image encryption scheme for color images based on quantum chaotic systems. In this scheme, a new substitution/confusion scheme is achieved based on toral automorphism in integer wavelet transform by scrambling only the Y (Luminance) component of low frequency subband. Then, a chaotic stream encryption scheme is accomplished by generating an intermediate chaotic key stream image with the help of quantum chaotic system. Simulation results justify the feasibility of the proposed scheme in color image encryption purpose.