Abstract: Based on digital image scaling, a secure steganographic model for batch steganography was proposed, which conformed to the absolute safety definition. After being divided into many blocks, the secret information was deduced by using image scaling algorithm, rather than directly embedded in the carrier images. Firstly, a batch of carrier images were selected and zoomed to a specified magnification through a specific algorithm, then the relevance of the pixel information between secret image blocks and new images could be found out, finally new images were reduced to size of the original images for transmission. Since the scheme did not directly modify the image pixels, the original images were not required for extracting secret images and the security of the stegosystem had been improved. The experimental results and analysis show that the proposed algorithm is effective and it can be applied to image concealed communication.

Key words: information hiding, batch steganography, image scaling, security

摘要： 采用数字图像的缩放算法，提出了一种符合绝对安全性定义的批量隐写模型。通过对隐秘图像进行分块，利用缩放算法推演隐秘信息，载体图像不直接携带隐秘信息。首先，选取n幅载体图像，通过特定算法将载体图像放大到指定倍数；然后，推出秘密图像的像素信息与新图像中像素信息的相关性；最后，再缩小为原图大小进行传输。由于未直接修改图像像素，提取密图不需原始图像，提高了隐秘信息的安全性。实验结果和分析表明了算法的有效性，适用于图像隐蔽通信。

关键词: 信息隐藏, 批量隐写, 图像缩放, 安全性