It is theoretically possible to eavesdrop on the computer data processing process by analyzing power line signals, but in practice it faces many technical challenges and limitations. The following is a detailed analysis： --- ### **1. Theoretical basis: Power line side channel attack** When a computer is running, its power consumption will dynamically change with data processing (such as CPU operations and memory accesses). This change may produce weak electromagnetic radiation or current fluctuations through the power cord. If an attacker can accurately monitor these changes and combine them with specific algorithms (such as **differential power consumption analysis DPA**), part of the data processing content can theoretically be inferred. --- ### **2. Practical feasibility** -**Signal strength and noise**： The noise on the power line (interference from other electrical appliances, fluctuations in the power grid) is much larger than the subtle signals generated by the computer. Extracting effective data requires high-precision sensors and complex filtering techniques. -**Data relevance**： It is difficult to directly obtain raw data (such as file content) only through power signals, but it is possible to speculate on the operating mode (such as the key bit of the encryption algorithm, the operating state of a particular program). -**Distance limit**： Direct eavesdropping usually requires physical proximity to the target circuit (as in a building), and remote access to the public power grid is almost impossible. --- ### **3. Known research cases** -**Academic experiment**： Some studies (such as experiments at Ben Gurion University in Israel) have proved that key input can be inferred by analyzing the power consumption of USB devices. But such attacks require a highly controllable environment. -**Advanced attack scenario**： National actors may use customized hardware implants (such as malicious power adapters) to achieve more accurate monitoring, but the cost is extremely high and requires physical contact. --- ### **4. Protective measures** -**Hardware level**： The use of power filter modules and electromagnetic shielding chassis can reduce signal leakage. -**Software level**： Constant-time algorithms (such as power consumption timing analysis) and randomized power consumption modes (such as dynamic voltage and frequency adjustment) can increase the difficulty of analysis. -**Physical security**： Restrict physical access to the power cords of critical equipment to prevent malicious equipment from accessing. --- ### **5. Real-world threat assessment** -**Risk to ordinary users**: Extremely low. Such attacks require professional equipment and technology, and usually only target high-value targets (such as the military and financial systems). -**Higher risk of substitution**： Traditional network attacks (malware, man-in-the-middle attacks) or physical intrusions (USB device implantation) are easier to implement and effective. --- ###**Conclusion** Power line signal analysis may disclose some information under **very specific conditions**, but it does not pose an actual threat to most scenarios. Security protection should give priority to more common attack vectors, while adopting hardware-level protection for highly sensitive environments.