Detecting Hardware Trojans (HTs) in digital circuits might be a challenging problem due to the stealthy nature of these malicious unwanted guests. The trigger part which is supposed to activate the Trojan under exceptional conditions, is often inserted at rare–switched nets of the design to hide them from usual verification tests mechanisms. Existing Trojan detection methods straggle in detecting modern Trojans which mostly have exploit multiple-input triggering parts to drive small payloads. Addressing such multiple-input triggering circuitries needs wise activation mechanisms with a reasonable time-complexity to serve as a feasible solution for large commercial designs. In this paper we present an algorithm which analyses fan-in and fan-out cones along with the Hardware Trojan susceptibility of the most suspicions nets of gate-level designs to find subsets of them which could most probably activate an inserted HT. Then a fast test vector generation algorithm is proposed to excite as many susceptible nets as possible for achieving the multiple nets excitation requirement. The results of applying the proposed algorithms on the TRIT and trust-hub benchmark suites show an average of 89% HT detection coverage while the required maximum run time is much smaller than the previous state of the art methods.

中文翻译：

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一种独立于触发器大小检测隐蔽硬件木马的有效技术

由于这些恶意不速之客的隐蔽性，检测数字电路中的硬件木马 (HT) 可能是一个具有挑战性的问题。应该在特殊条件下激活特​​洛伊木马的触发器部分通常插入设计的罕见交换网络中，以将它们隐藏在通常的验证测试机制之外。现有的木马检测方法在检测现代木马方面表现不佳，这些木马大多利用多输入触发部分来驱动小负载。解决此类多输入触发电路需要具有合理时间复杂度的明智激活机制，以作为大型商业设计的可行解决方案。在本文中，我们提出了一种算法，该算法分析扇入和扇出锥以及门级设计的最可疑网络的硬件木马易感性，以找到最有可能激活插入的 HT 的子集。然后提出了一种快速测试向量生成算法，以激发尽可能多的易感网络，以实现多网络激励要求。在 TRIT 和 trust-hub 基准套件上应用所提出的算法的结果显示平均 89% 的 HT 检测覆盖率，而所需的最大运行时间远小于以前的最先进方法。然后提出了一种快速测试向量生成算法，以激发尽可能多的易感网络，以实现多网络激励要求。在 TRIT 和 trust-hub 基准套件上应用所提出的算法的结果显示平均 89% 的 HT 检测覆盖率，而所需的最大运行时间远小于以前的最先进方法。然后提出了一种快速测试向量生成算法，以激发尽可能多的易感网络，以实现多网络激励要求。在 TRIT 和 trust-hub 基准套件上应用所提出的算法的结果显示平均 89% 的 HT 检测覆盖率，而所需的最大运行时间远小于以前的最先进方法。