大容量自适应隐写对抗的博弈研究

摘要

攻击方拥有自适应规范边信息条件下，如何提高大容量自适应隐写的安全性成为亟待解决的问题。本文对大容量自适应隐写方和攻击方进行博弈建模，分析了博弈均衡存在的条件，通过理论证明给出均衡局势下隐写对抗双方的混合策略和期望支付，最后利用仿真实验验证了理论分析的正确性。研究表明，攻击方的策略与嵌入的信息量无关，期望支付随着嵌入信息量的增加而增加；隐写方选择在载体中某位置进行较多嵌入的概率随着该位置的复杂度增加而增加且不为零。该结论对设计安全的大容量自适应隐写具有一定的指导意义。%Given that the attacker has the side information of adaptivity criterion ,it is an urgent problem for the steganogra-pher to improve the security of large-payload and adaptive steganography .This paper proposed a game-theoretic model for the two sides .Through theoretical derivation ,we provided the necessary conditions for game equilibrium ,along with the mixed strategies and expected payoffs of the two sides in equilibrium .Results of numerical simulation validated the theoretical analysis .This research re-veals that the attacker’s strategy is independent of the number of hidden bits ,and the expected payoff increases with the number of hidden bits .The probability that one position is selected by steganographer to embed more bits is always greater than zero and in-creases with the complexity of that position .These conclusions bring some guidance for devising secure adaptive steganography with large payload .