The high cost of integrated circuit chip production has driven more and more chip design companies to use overseas production services. Since the integrated circuit production cannot be closely monitored, the security of integrated circuit chips has become a major concern. Hardware Trojan (HT) insertion is one type of the hardware attack. HTs are extremely stealthy due to their small sizes and low triggering rates. HTs inserted during manufacturing can have minimum impact on the timing and power. In fact, this impact can be smaller than the timing and power variations caused by the process variations. Therefore, these HTs cannot be easily detected using traditional electrical methods. In this article, we propose a novel optical method, where we image the integrated circuit chip from the backside. Our method, can easily detect any replacements, modifications, or rearrangements of fill cells or functional cells for HT insertion. We use a noise-based detection method to achieve high HT detection rates in different testbenches. To further improve the robustness of our method, we strategically place high reflectance fill cells in the designs. Our approach provides high-resolution, nondestructive, and rapid means to detect HTs inserted during fabrication. We evaluate our approach using various hardware blocks where the HTs can occupy less than 0.1% of the total area or consist of fewer than three gates. In addition, we analyze our method with various magnitudes of noise, process variations, detection window sizes, and resolutions.

中文翻译：

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使用背面光学成像检测硬件木马


集成电路芯片生产成本高昂，促使越来越多的芯片设计公司采用海外生产服务。由于集成电路生产无法严密监控，集成电路芯片的安全性成为人们关注的焦点。硬件木马（HT）插入是硬件攻击的一种。 HT 由于尺寸小且触发率低，因此极其隐蔽。在制造过程中插入的 HT 对时序和功率的影响最小。事实上，这种影响可能小于工艺变化引起的时序和功率变化。因此，使用传统的电学方法无法轻易检测到这些HT。在本文中，我们提出了一种新颖的光学方法，从背面对集成电路芯片进行成像。我们的方法可以轻松检测用于 HT 插入的填充单元或功能单元的任何替换、修改或重新排列。我们使用基于噪声的检测方法在不同的测试平台上实现高HT检测率。为了进一步提高我们方法的稳健性，我们在设计中战略性地放置了高反射率填充单元。我们的方法提供了高分辨率、无损且快速的方法来检测制造过程中插入的 HT。我们使用各种硬件块来评估我们的方法，其中 HT 可以占用不到总面积的 0.1% 或由少于三个门组成。此外，我们还使用各种噪声幅度、过程变化、检测窗口大小和分辨率来分析我们的方法。