RogerKint
Member
- Location
- California
- Occupation
- General Electrician
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SCIF Wall Penetration Grounding
- Thread starter RogerKint
- Start date
petersonra
Senior Member
- Location
- Northern illinois
- Occupation
- engineer
because someone put it in the spec. it is likely that any size wire would work, or no wire at all even.In a govt facility the spec requires grounding all SCIF wall penetrations with a #4 copper wire. Why #4?
SCIF construction requirements are defined in document ICD705. Shielding/TEMPEST is up to the specific agency to define and there is a guidance book but it is restricted. They will definitely want all metal penetrations grounded and probably have short non-metallic sections installed too but this isn't always possible (e.g. heat pump refrigerant pipes). The specific grounding conductor required may not be defined or may be up to the CTTA (TEMPEST Authority) to define. I specified requirements for at least 2 SCIFs and I think I also specified #4 for grounding the metal pipe penetrations. There are many detail questions to answer when building a SCIF because the documents suck and they hid a bunch of the pages from me. Seems like each authority will have in their head what they want to see and you don't find out until you have to do it over. Just because you do a SCIF one way doesn't mean you'll do it the same way next time.
Maybe like all other grounding it is because it is difficult not to? They utilize a single point ground approach, but this single point ground also goes to the power filter box and that box is grounded to the electrical source. Metal piping also tends to be grounded, and our architect did not like non metallic segments in sprinkler piping because of all the flooding that happened in past earthquakes.
RogerKint
Member
- Location
- California
- Occupation
- General Electrician
The job is still on going and we haven’t done this required bonding yet. I have asked everyone possible including the heads of security, no one has any clue why this extra bonding is required or what it even prevents. Seems like something they made up regarding cold war paranoia.
The reasons why are classified. Gets into sources and methods.
I think the original demonstration of TEMPEST vulnerabilities was at a computer trade show. One vendor had a device that could tune to the monitors in the other booths by picking up the RF emissions and fine tuning to choose different displays. Now days there are probably many more ways to do this. It could also be something as simple as if they smuggle a cellphone into the SCIF, we dont want the phone, bluetooth, or wifi signals to go anywhere.
I think the original demonstration of TEMPEST vulnerabilities was at a computer trade show. One vendor had a device that could tune to the monitors in the other booths by picking up the RF emissions and fine tuning to choose different displays. Now days there are probably many more ways to do this. It could also be something as simple as if they smuggle a cellphone into the SCIF, we dont want the phone, bluetooth, or wifi signals to go anywhere.
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