Think your phone is snooping on you? Hold my beer, says basic physics

Information wants to be free, and it's making its escape

Opinion Forget the Singularity. That modern myth where AI learns to improve itself in an exponential feedback loop towards evil godhood ain't gonna happen. Spacetime itself sets hard limits on how fast information can be gathered and processed, no matter how clever you are.

What we should expect in its place is the robot panopticon, a relatively dumb system with near-divine powers of perception. That's something the same laws of physics that prevent the Godbot practically guarantee. The latest foreshadowing of mankind's fate? The Ethernet cable.

By itself, last week's story of a researcher picking up and decoding the wireless emissions of an Ethernet cable is mildly interesting. It was the most labby of lab-based demos, with every possible tweak applied to maximise the chances of it working. It's not even as if it's a new discovery. The effect and its security implications have been known since the Second World War, when Bell Labs demonstrated to the US Army that a wired teleprinter encoder called SIGTOT was vulnerable. It could be monitored at a distance and the unencrypted messages extracted by the radio pulses it gave off in operation.

The same is true of everything that uses electricity to carry data, leading to spooky/anti-spooky efforts like TEMPEST to either utilise or minimise the problem. What it can never do is solve it. Physics, man. It's how the electromagnetic or EM quantum field works, one of the five basic forces of the cosmos (the other four being gravity, strong atomic, weak atomic, and stupidity, since you ask). Good luck turning that off with a driver patch.

The EM field works its magic through one weird trick. If you change the speed of an electron, which all electronics does all the time, it gives off electromagnetic waves. Can't help it. You can scramble the signal, you can minimise it, you can try to shield it, but it's there and it can be picked up if you try hard enough. Any piece of wire can be an antenna. It's the world's simplest machine and it will radiate if tickled.

Ethernet has a lot of electrons rushing about through long wires, and thus has a lot of design features to minimise its radiation. Cables use twisted pairs of conductors, which to some extent cancel out the wireless leaks. You can buy special shielded cabling, which is even better – but it's expensive and needs to be properly installed and maintained. You don't do that. And the faster Ethernet has become, the more efficiently even short cables couple their noise into the ether. Doubt it? Get an analogue radio, tune to a dead spot on the dial, and put it near a busy piece of gigabit string.

So, if every Ethernet system is hissing secrets into the void, who's listening? Excluding your actual spies, it would seem nobody. Quite the opposite. Every bit of wireless kit on the planet tries hard not to listen, because most of the time your packets are just interference. These days, this filtering process is often a software function, and increasingly it knows a lot about the interference it's trying to reject – and listens to it quite closely to cancel it out, just like the microphones in noise-cancelling headphones.

Guess what? Our new friendly AI/ML is poking its snout in. Yes, it will end up using the data it's trying to cancel out to build up patterns. And yes, that's the same as listening really hard to it. Will this data, collected invisibly by automatic agents and potentially containing useful behavioural signals, be safe from exploitation? You can answer that yourself.

This is just one example. You only have to go back a few weeks to find another, with the announcement of a system where fibre-optic cables were used to pick up sound ostensibly to sense when they're about to be dug up by mistake. This time, the underlying physics is that when you send light through a medium, it is affected by the physical attributes of that medium, which change when it's compressed by, say, sound. Not can be. Not maybe. It is. Do the right pattern analysis on this, and you can tell a lot about where and what the sound is. Instead of leaking information, the fibre becomes an immensely long microphone. It always was, but now we have the appropriate magic to use it as such.

Do walls have ears? If you bounce Wi-Fi signals off them and look for tiny changes caused by sound waves, yes they do. If they've got Cat 6 running through them, they've got mouths too.

That is how it's going, chums. Everything is connected, everything affects everything else. We live in a universe which loves to preserve, propagate, and transform information, and we're getting very good at using that in new, exciting, and disturbing ways, always with pattern recognition and increasingly amplified by AI/ML. Which isn't very good at thinking but is exceptionally good at sifting information from noise.

We'll still have to do the thinking if we want our new eavesdropping planet to be a nice place to live. ®

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