Abstract: Aiming at the problems of carrier image quality degradation and capacity redundancy in existing image steganography, a quantum image steganography scheme based on least significant bit (LSB) and turtle shell is proposed. The scheme divides the quantum carrier image into contiguous non-overlapping blocks, then the block properties are classified into edge or smooth according to the maximum pixel difference in each block, and the LSB or turtle shell substitution algorithm is selected accordingly to hide the secret information. Specifically, the LSB algorithm is improved in this scheme by modifying the two least significant bits of the carrier image to achieve the secret information embedding of three bits. At the same time, the distance comparison in traditional turtle shell algorithm is removed, so that the number of correlation points is reduced. On this basis, the adjacent quantum bits in the quantum image are exchanged to preprocess the secret image, and corresponding quantum circuits are constructed. The simulation experiment results show that the proposed scheme has superior performance in imperceptibility, embedding capacity and robustness.

Key words: image processing, quantum image steganography, least significant bit, turtle shell steganography algorithm