Small aircraft with streaming video cameras are now widely available, for better or worse. Making eyes in the sky so accessible has resulted in interesting footage that would have been prohibitively expensive to capture a few years ago, but this new creative frontier also has a dark side when used to violate privacy. Those who are covering their tracks by encrypting their video transmission should know researchers at Ben-Gurion University of the Negev demonstrated such protection can be breached.
The BGU team proved that a side-channel analysis can be done against behavior common to video compression algorithms, as certain changes in video input would result in detectable bitrate changes to the output stream. By controlling a target’s visual appearance to trigger these changes, a correlating change in bandwidth consumption would reveal the target’s presence in an encrypted video stream.
The idea demonstrated here is early and share challenges common with every side-channel attack: teasing signal out of noise. The signal may be misinterpreted resulting in a false positive, or the technique can be circumvented by adding more noise. Future research will surely pursue both fronts, just as surely as some FPV equipment makers will work to evade detection (careful what frequencies you use) and some people will take a more direct approach to deterrence.