A novel quantum image steganography algorithm based on exploiting modification direction

Quantum image steganography is the art and science of hiding secret information into quantum carrier images. This paper proposes a novel quantum image steganography algorithm based on an efficient embedding technique of exploiting modification direction. For convenience, this embedding technique is referred to the EMD embedding. In the EMD embedding, it is clear that each carrier pixel-group of the carrier image contains N pixels and each secret digit of secret information belongs to the (2N + 1)-ary notational system, where N is a system parameter. The embedding process is that at most only one pixel of the carrier pixel-group will be either increased by 1 or decreased by 1. The new algorithm takes advantage of the EMD embedding owning high embedding efficiency that the (2N + 1) different modifications to N carrier pixels represent the value of the secret digit. In addition, designing the dedicated quantum circuit for the EMD embedding contributes to better understanding the process of the new algorithm. Experimental simulation based on MATLAB shows that the new algorithm has good performance on imperceptibility, security, embedding efficiency and embedding capacity.