Security researchers from Uruguay’s University of the Republic have demonstrated a method to spy on screen contents by intercepting electromagnetic radiation from video cables using AI. This technique can reconstruct screen images from HDMI signals with about 70% accuracy, suggesting that such attacks might already be happening.
Historically, hackers could easily reconstruct screen contents from analog video cables due to their simpler signal leakage. Digital protocols like HDMI, while more complex, still emit some electromagnetic radiation. By training an AI model on both original and intercepted HDMI signals, the researchers were able to decode these leaks into readable screen captures.
Their method successfully reconstructed text from intercepted HDMI signals with 70% accuracy. This level of precision allows for deciphering sensitive information such as passwords, financial data, or encrypted communications. Using text recognition software on the visuals recovered by the AI model, the team improved the error rate by 60% compared to previous techniques.
In practical scenarios, hackers could implement HDMI eavesdropping by planting a discreet signal-capturing device inside the target building or using a nearby radio antenna to capture leaked HDMI radiation.
The researchers indicate that these attacks are already being used against government agencies and sensitive industrial settings, which typically shield their facilities against electromagnetic leaks despite the high cost. For average home or office users, the barrier to entry for this HDMI hacking method remains high due to the complexity of deploying AI models and signal-capturing equipment.
Lead researcher Federico Larroca reassures that while governments may be concerned about this, average users need not be overly worried. However, for those highly concerned about security, this method could pose a threat. For now, there’s no need to discard HDMI cables, but be cautious of suspicious activities, such as vans parked nearby, when accessing sensitive information.
