Video-Based Cryptanalysis: Extracting Keys from Power LEDs

Explore a groundbreaking DEF CON 31 conference presentation that introduces video-based cryptanalysis, a novel technique for extracting secret keys by analyzing power LED footage from non-compromised devices. Learn how cryptographic computations performed by device CPUs influence power consumption, resulting in detectable changes in LED brightness and color. Discover how to leverage a video camera's rolling shutter to dramatically increase sampling rates, enabling effective cryptanalysis through RGB value analysis of captured frames. Follow practical demonstrations of key recovery, including a 256-bit ECDSA key extraction from a smartcard reader using a remote security camera at 16 meters, and a 378-bit SIKE key recovery from a Samsung Galaxy S8 using iPhone 12 footage of USB speaker LEDs. Examine the implications, limitations, countermeasures, and future prospects of this innovative cryptanalysis method.