[Cryptography] Regulations of Tempest protections of buildings

Jerry Leichter leichter at lrw.com
Wed Apr 5 15:36:00 EDT 2017


> You yourself are wrong  in my view.  For 47 USC 333, states that
> "No PERSON shall willfully or maliciously interfere with or cause interfearence to .......",  not
> "No DEVICE shall......."
> 
> Via building a Farady cage, a person ..... causes interference to ......, right?
Those in the relevant field (electrical engineering) would not interpret the word "interfere" to include Faraday cages.  (They also wouldn't include something like turning off power to an active transmitter.)

Could some enterprising lawyer try to make the case that "interfere" encompasses this kind of activity?  Sure - we've seen enterprising lawyers do much worse.  Generally they don't succeed - courts are not that stupid.

I would accept your claims if you could point to any case where the FCC went after someone for building a Faraday cage.

BTW, the closest cases on point might involve buildings that are deliberately configured to block cellphone signals.  You can, in fact, buy conductive paint and wallpaper for this purpose.  On the other hand, devices that actively transmit in the cell phone bands in order to block cell phone usage are definitely illegal, and the FCC has gone after those who sell and use such devices.

Law is not about theory.  Law is all practical application.  Looking at the exact wording of regulations won't teach you much.
                                                        -- Jerry



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