【摘要】 为了减少硬件木马对可控制性低的节点的依赖,设计了一种对木马植入节点和内部结构进行改进的方法.针对木马插入点,提出了一种从可控制性高的节点中寻找存在低概率组合的节点搜索算法.针对木马内部低概率节点,提出了基于非稀有事件和多节点控制攻击路径的木马模型.在ISCAS-85基准电路上进行实验,对比了基于低概率和基于组合概率的选点方法的木马触发概率,并实现了一个基于所提方法的6输入端的木马设计.实验结果表明,随着触发端口的增多,基于组合概率的木马可以实现与基于低概率节点的木马相当(甚至更低)触发概率的效果,而基于非稀有事件的木马设计可以消除木马内部直接影响木马触发的低概率节点,避免木马被自动测试矢量误触发,提高木马隐蔽性.更多还原

【Abstract】 To reduce the dependency of hardware Trojan on low-controllability nodes,a method for improving the implanted node selection and the internal structure of hardware Trojan was designed.For Trojan implanted nodes,a node searching algorithm for finding low-probability combination from high-controllability nodes was proposed. For low-probability nodes inside Trojan,a Trojan design model based on non-rare events and multi-nodes controlling attack path was presented. By the ISCAS-85 benchmark circuit,the triggering probabilities of Trojans based on low-probability nodes and the combination probability are compared,and a Trojan design with 6-inputs based on the proposed method was realized. The experimental results show that the hardware Trojans based on combination probability can achieve a comparable( or even lower) triggering probability with that based on low-probability nodes when the numbers of Trojan triggering ports increase. And Trojan internal nodes with a direct impact on Trojan triggering probability can be eliminated by the Trojan design based on non-rare events,protecting Trojan from being triggered by auto-test patterns. Thus,improving the concealment of hardware Trojan.更多还原