Multi-image secret sharing for general access structure without size expansion

Abstract

In some scenarios with high-confidentiality requirements, some participants need to be authorized with decoding capabilities. Moreover, simultaneously transferring two kinds of secret information can improve sharing efficiency without adding extra storage space. This paper proposes a general access structure for multi-image secret sharing (GAS-MISS) without size expansion. The integer linear programming that can be used to achieve the iterative sharing and filtering operation is established by setting the constraint. Therefore, the grayscale value of shares satisfying the constraint condition is obtained. In other words, this process simultaneously encodes two kinds of different secret images. Besides, through the input GAS, the threshold of our scheme is not restricted. With different computational complexity schemes, the original two secret images are reconstructed. The experimental results confirm the correctness and advantages of the proposed scheme. Compared to previous schemes, GAS-MISS can generate two kinds of secret images in high-security scenarios. Meanwhile, the shares do not have the burden of pixel expansion.