They can reconstitute private keys, by listening repeatedly to the sound the power supply of a laptop makes when encrypting/decrypting emails, from 5m away.
I’ve considered implementing this as a keyboard layout in Android, so you could put your phone on the desk and type by scratching a stylus or fingernail on the surface next to it.
Some of us are even familiar with acoustic cryptoanalysis[0].
However, combine these methods with this[1] tech, inspired on the work done here[2], and we have ourselves an impending crisis on our hands.
[0] Acoustic Cryptoanalysis - https://courses.csail.mit.edu/6.857/2014/files/23-shroff-hu-...
[1] Extracting Audio From Visual Information - https://news.mit.edu/2014/algorithm-recovers-speech-from-vib...
[2] Eularian Video Magnification - https://people.csail.mit.edu/mrub/papers/vidmag.pdf
Let's run through a scenario.
Your office orders pizza every Tuesday at the same time, via a coworker's cell phone. You are working on a technology that has the potential to disrupt several leading industries that are in bed with the government. After much lobbying, it is decided one day that your call to Domino's is to be rerouted via your broadband processor to an operative that mirrors your order to the real Domino's, and hand delivers the pizza at the front desk.
On their way out, they place a small, embedded, self-destructable camera device that focuses on your fancy new plexiglass installment. Over the next few weeks, the device documents all keystrokes and conversations from the front desk, and finds a way to socially engineer a copy of your codebase. Next year, seemingly out of nowhere, another venture suddenly launches ahead of your launch schedule, with your exact business model. All because you wanted some plexiglass and didn't think it was worth the money to actively scan the entire perimeter for bugs daily.
If this sounds crazy and far-fetched to anyone, then it would behoove them to look into past CIA infiltration techniques and also to realize that this is exactly the kind of stuff the CIA exists to do.
I think one can tend to create similar gibberish over time. I've worked on a system where I needed to do a new signup every time I wanted to test a feature and I've run into issues where the gibberish I entered matched an account that I had previously created.
[0] http://www.berkeley.edu/news/media/releases/2005/09/14_key.s...
In my university days, long before the days of tablets and smartphones, the computer labs were the usual place where people will congregate to do their assignments or basically kill time on the internet in between classes.
One day, my mates and I noticed how annoyingly loud some people type on their keyboards and out of sheer boredom, we decided we could come up with an algorithm to determine what a person was typing simply from recording the sound of the keystrokes from our vantage point. Taking that sound clip, we graphed it out and we proceeded to hash out each "stroke" based on how loud it was in relation to the distance of where we were from the keyboard + the angle of the keyboard.
Fun times ensued. ;)