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Comment by hengheng | Hacker News Reader

I don't know who the audience for this article is, whether it's hardware people struggling to pass regulatory compliance, or whether it's paranoid people thinking they can somehow escape surveillance.

For passing certification, the best advice is really shielding closest possible to the source. Bury all signals, have no cables, shield the die if anything. If you can, bury the die.

For escaping surveillance, make sure to never leave the shielded room, or meet with people who do. /s

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This is a trade magazine for people who assemble systems from components. So they put a router in a box, or whatever, and need a power supply and amplifier and connectors to the outside world. The finished system needs to pass compliance testing, but they can't modify the parts they've selected - all they can do is fix the cabling and do things to the outside of the purchased components.

It's kind of like EMI/EMC testing of hardware you have designed yourself; it's usually much cheaper to apply a bandaid fix (add ferrite cores, shield that cable better, terminate here not there, etc.) and add to a punch list for rev 2, than to go back to the drawing board and change the board/die/whatever.

Of course if you can plan for this during design, you (and your boss/bottom line!) will be a lot happier.

In the mid 90s I had the dubious pleasure of being asked to repair a series of TEMPEST certified computers: standard Zenith 8086 clones (well, as standard as a Zenith got anyway) inside a massive steel chassis with all inputs/outputs wrapped around multiple ferrite cores before passing through some heavy-duty milspec connectors. Took a solid couple of minutes each machine pulling screws just to get the lid off so I could plug in a keyboard and monitor (Hercules Monochrome!) and assess the system. Took a dozen machines and made four or five working ones - lot of hard drive failures though Spinrite did manage to resurrect a couple. Still remember all those little jumper leads going from the peripheral cards through the ferrites and into the funky round connectors on the outside of the box.

my isp has a built in public (captive portal) wifi network that I can't turn off. They use it to provide wifi hotspots all over the country. rf shielding is a non destructive mod I can do to block the rogue wifi

if this is Comcast, you can also just buy your own modem/router

I believe you can also turn it off in your account settings.

it has been known to turn itself back on. for comcast, besides buying your own, you can also request a non-wifi router.

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