基于图像混沌块置乱和DWT变换的无载体信息隐藏研究

Coverless Information Hiding Based on Chaotic Scrambling of Image Blocks and DWT Transform

无载体隐写通过提取载体特征,与信息序列进行映射,从而无需修改载体即可实现对秘密信息的隐藏,因此,具有极强的抗隐写分析能力,但是已有算法在隐藏容量方面仍然有限,且大多需要构建大样本图像库。本文提出一种基于混沌块置乱和离散小波变换(Discrete wavelet transform,DWT)的无载体信息隐藏算法,从秘钥中提取混沌变换的相关参数,对载体图像进行混沌块置乱生成多张新图像,再对其进行分块DWT变换,根据相邻图像块低频DWT系数之间的关系生成对应的哈希序列,并构建相应索引库。将载体图像及秘钥发送给接收方,实现秘密信息的传递。实验表明,与现有算法相比,该算法获得了隐藏容量和隐藏成功率的较大提升,具有较强的鲁棒性。同时,该算法架构简单,传输负载小,具有较强的实用价值。

Coverless steganography can hide the secret information without modifying the carrier by extracting the features of the carrier and mapping with the information sequence.Therefore,it has strong ability of anti-steganalysis,but the existing algorithms are still limited in hiding capacity,and most of them need to construct a library with large number of images.In this paper,a coverless steganography algorithm based on image block chaos scrambling and discrete wavelet transform(DWT)is proposed.The parameters of chaos transform are extracted from secret key,and the cover image is scrambled to generate multiple new images.Then,block DWT transform is used to generate the corresponding hash sequence according to the relationship between the low-frequency DWT coefficients of adjacent image blocks,and corresponding index library is constructed.The cover image and secret key are sent to the receiver to realize the transmission of secret information.Experimental results show that compared with the existing algorithms,the proposed algorithm not only has a great improvement on the capacity and success rate of information hiding,but also has strong robustness.At the same time,the algorithm has a simple architecture and small transmission load,which shows strong practical value for application.