Haha. I won't go that far. You just shield from as many forms of sounds, light, EM, etc as you can. Alternatively, build memory and info-flow security into your hardware, do POLA at device level, and use TEMPEST-style hardware. Also, as in EMSEC tents or safes, one can separate security levels into their own shielded cages/racks. Already products for that although not sure if energy gapping is thorough enough.
Not so trivial, then.