Video-Based Cryptanalysis: Extracting Cryptographic Keys from Video Footage of a Device’s Power LED
The paper introduces video-based cryptanalysis, a novel method for recovering secret keys from devices. It exploits the relationship between the power consumption of a device’s CPU and the brightness of its power LED. By analyzing video footage of the power LED, attackers can use commercial video cameras to recover secret keys. The rolling shutter feature of these cameras allows for a significant increase in sampling rate, enabling precise measurements. The RGB values of the analyzed frames are used to induce the power consumption and recover the secret key. The paper demonstrates two successful attacks, recovering a 256-bit ECDSA key from a smart card and a 378-bit SIKE key from a Samsung Galaxy S8. Countermeasures, limitations, and the future prospects of video-based cryptanalysis are also discussed, taking into account advancements in video camera specifications.
