EAGER: Exploration of THz Backscattering as a Side-channel in Computer Systems

该项目研究了一种新的侧信道信息，攻击者可以使用它来学习计算机芯片设计。这对于推进科学了解这一侧面渠道的脆弱性非常重要。一种新的边信道，称为太赫兹频率（THz）后向散射，是本项目的重点。计算机系统实际上不直接发出太赫兹频率信号。相反，THz信号被传输到目标系统的所需部分并被反射回来。信号包含有关系统目标部分活动的信息，因为信号的反射取决于其反射材料的阻抗，因此反射信号由入射THz光束的目标区域中（或连接到目标区域中的金属线）的任何晶体管的开关状态调制。该项目将构建有史以来第一个THz背散射侧通道测量测试平台，使用该测试平台评估系统板，芯片引脚和芯片内电路的THz背散射的关键特性，并表征THz背散射在各种使用场景中的优点和缺点，例如作为特定芯片的“签名”，作为对照“已知良好”参考验证芯片活动的方式、作为潜在威胁（当用于侧信道攻击时）等。

This project looks into a new side channel information that attackers can use to learn a computer chip design. This is important for advancing the science for understanding what vulnerabilities there are from this side channel. A new side-channel, which is called Terahertz-frequency (THz) backscattering, is the focus of this project. A computer system directly emanates virtually no THz-frequency signals. Instead, a THz signal is transmitted toward the desired part of the targeted system and is reflected back. The signal contains information about the activity in the targeted part of the system because the signal's reflection depends on the impedance of the material it reflects from, so the reflected signal is modulated by the switching state of any transistors that are in the target area (or connected to metal wires that are in the target area) of the incoming THz beam. The project will construct the first-ever measurement testbed for THz backscattering side-channels, use this testbed to evaluate the key properties of THz back-scattering from system boards, chip pins, and circuitry within a chip, and characterize the advantages and disadvantages of THz back-scattering for various use scenarios, e.g. as a "signature" of a specific chip, as a way of validating a chip's activity against a "known good" reference, as a potential threat (when used for side channel attacks), etc.