为了提高隐写算法的安全性,提出一种基于Fisher信息的最优隐写框架.将隐写算法设计建模成以嵌入转移概率为决策变量、以Fisher信息最小化为目标的最优化问题.推导出Fisher信息是嵌入转移概率的二次型,通过二次规划求解最优嵌入转移概率.给出了一个最优隐写算法实例——最优LSBmatching算法,实验结果表明,最优LSBmatching算法的Fisher信息小于传统LSBmatching算法,隐写安全性提高.
This paper proposes an optimal steganography framework based on Fisher Information. An embedding algorithm is designed to solve the optimization problem whose objective is minimizing the Fisher Information of a steganographie system. The Fisher Information is the quadratic form of the embedding transferring probabilities. The problem of optimal embedding transferring probabilities is solved by quadratic programming. Then the optimal LSB matching algorithm, which is an instance of the optimal steganographic algorithm, is given. The experimental results show that the Fisher Information of the optimal LSB matching is smaller than that of the conventional LSB matching and the security of the optimal LSB matching is better.