4 ms·
It's a cat and mouse game as you probably surmise. What the surveillant wants is a clear signal with features corresponding to known information. The surveilee
by nonrandomstring 4y ago
It's a cat and mouse game as you probably surmise. What the
surveillant wants is a clear signal with features corresponding to
known information. The surveilee tries to send noise that most
closely mimics those features, so the signal is lost in, and cannot be
separated from, that noise. The adversaries each try to find a space
unknown to the other (much like cryptography - cryptanalysis) (and
undiscoverable by the other in a viable timeframe/information set)
For example, speech was traditionally though to be well masked by
white noise. But modern filter technology makes short work of removing
broadband noise even if the signal is fully buried in it. Instead we
now use speech-like fragments as an adversarial mask, as close to the
speaker's spectrum and timing as possible.
In terms of computational cost it's not a big deal. If it _can_ be
removed it probably can in real-time by a well equipt agent.
- transpute 4y agoIs there a Metasploit equivalent for wireless cat-and-mouse games? If not, what would it take to start one, e.g. live CD with pre-configured GNU radio code/plugins that is compatible with low-cost and USRP SDRs? An awesome-wifi-sensing list could be a starting point for aggregation of OSS projects.
- nonrandomstring 4y agoI've no doubt you can do all the necessary number crunching in Octave/Matlab to implement things like a time-domain reflectometer - the DSP is well known in domains like seismology for prospecting, artillery ranging and calculating room shape from sound, as with the image source method. I think the hard part for an amateur lab is antenna stuff. I am not an RF engineer, nor have I read the linked papers in detail, but I'm guessing that to do this well you need phased arrays or multiple directed YAGI style elements - because all the methods I know from acoustics use multiple microphones, often closely calibrated etc.
- transpute 4y agoThere's 1000+ papers on attackers using Wi-Fi sensing, but almost none on defenses, https://scholar.google.com/scholar?cites=4354757827101869878 https://scholar.google.com/scholar?cites=4354757827101869878 Wi-ESP is an OSS project for Wi-Fi sensing with low-cost ESP32 devices, https://wrlab.github.io/Wi-ESP/ https://wrlab.github.io/Wi-ESP/ & https://academic.oup.com/jcde/article/7/5/644/5837600 https://academic.oup.com/jcde/article/7/5/644/5837600