Secret image sharing with distinct covers based on improved Cycling-XOR

Secret image sharing (SIS) is a technique used to distribute confidential data by dividing it into multiple image shadows. Most of the existing approaches or algorithms protect confidential data by encryption with secret keys. This paper proposes a novel SIS scheme without using any secret key. The secret images are first quantized and encrypted by self-encryption into noisy ones. Then, the encrypted images are mixed into secret shares by cross-encryption. The image shadows are generated by replacing the lower bit-planes of the cover images with the secret shares. In the extraction phase, the receiver can restore the quantized secret images by combinatorial operations of the extracted secret shares. Experimental results show that our method is able to deliver a large amount of data payload with a satisfactory cover image quality. Besides, the computational load is very low since the whole scheme is mostly based on cycling-XOR operations.