Video display units (VDUs) using differential signaling technology significantly increase the risk of compromising video information security through leakage emissions. This article shows that differential signaling cables act as substantial video leakage sources. A concept is proposed that explains the video leakage principles of VDUs using differential signal cables such as the high-definition multimedia interface (HDMI) cable, digital visual interface (DVI) cable, and the low-voltage differential signaling (LVDS) cable. The emanations of the LVDS cable are closely examined by measuring simultaneously the differential video signal on the LVDS lines and its near- and far-field leakage emissions. From these measurements, several conclusions are drawn that give new insights into the video eavesdropping risk of VDUs using differential signaling methods. Furthermore, a novel video image reconstruction method is proposed that exploits the compromising emanations of a VDU by using frequency demodulation techniques. This article shows that leaked video emanations of VDUs using differential signaling cables are not only amplitude modulated (AM) but also frequency modulated (FM). This strongly implies that the possible algorithmic toolset of malicious video eavesdroppers is much larger than currently assumed. This article investigates several VDU setups at a distance of 10 m, including an ultrahigh-definition video display, three different HDMI cables and two notebooks. Additionally, the AM-based and FM-based video image reconstruction results are discussed and compared.

中文翻译：

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差分信号通过 AM 和 FM 泄漏辐射危及视频信息安全

使用差分信号技术的视频显示单元 (VDU) 通过泄漏发射显着增加了危及视频信息安全的风险。本文表明，差分信号电缆是重要的视频泄漏源。提出了一个概念来解释使用差分信号电缆的 VDU 的视频泄漏原理，例如高清多媒体接口 (HDMI) 电缆、数字视频接口 (DVI) 电缆和低压差分信号 (LVDS) 电缆。通过同时测量 LVDS 线路上的差分视频信号及其近场和远场泄漏发射来仔细检查 LVDS 电缆的发射。从这些测量中，得出的几个结论为使用差分信号方法的 VDU 的视频窃听风险提供了新的见解。此外，提出了一种新的视频图像重建方法，该方法通过使用频率解调技术来利用 VDU 的妥协发射。本文表明，使用差分信号电缆泄露的 VDU 视频发射不仅是调幅 (AM)，也是调频 (FM)。这强烈暗示恶意视频窃听者的可能算法工具集比目前假设的要大得多。本文研究了 10 m 距离内的多个 VDU 设置，包括超高清视频显示器、三种不同的 HDMI 电缆和两台笔记本电脑。此外，还讨论和比较了基于 AM 和基于 FM 的视频图像重建结果。