Abstract:

To solve the problem of active attack on steganographic system, the counterwork relationship was modeled between steganographier and active attacker. The steganographic game with embedding rate and error rate as the payoff function was proposed. With the basic theory of two-person finite zero-sum game, the equilibrium between steganographier and active attacker was analyzed and the method to obtain their strategies in equilibrium was given. Then an example case was solved to demonstrate the ideas presented in the model. This model not only provides the theoretic basis for steganographier and active attacker to determine their optimal strategies, but also brings some guidance for designing steganographic algorithms robust to active attack.

Key words: covert communication, steganographic system, active attack, game theory, embedding rate, bit error rate

摘要：

针对隐写系统面临的主动攻击问题，对隐写方和主动攻击方之间的对抗关系进行建模，提出了以信息嵌入率和错误率两个目标为收益函数的隐写系统博弈模型。借助二人有限零和博弈基本理论，分析了隐写方和主动攻击方博弈均衡的存在性，并给出了均衡局势下对抗双方的策略求解方法。最后通过求解一个实例说明了模型的有效性。建立的模型可为隐写方和主动攻击方的最优策略选择提供理论依据，对抗主动攻击的隐写算法设计也具有一定的指导意义。

关键词: 隐蔽通信, 隐写系统, 主动攻击, 博弈论, 嵌入率, 错误率