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Ethernet Wiring Through Hostile Territory?
GoogleDidntFindIt asks: "I need to connect a terminal to a server which contains very sensitive information. Unfortunately, the terminal is about 200 feet away from the server. The server (which even includes a 'self destruct' device) and terminal are both in highly secure areas of the building, but the wiring will be in uncontrolled areas. What should I do to keep people from tapping or monitoring the wire?" Is there any way a conduit can be wired with an alarm which goes off when it's integrity has been violated?
"Heres a basic description of my situation:
- A new wire/fiber/cable/whatever will be run and I can use any sort of conduit I want.
- A potential attacker may have several days of undetected access to parts of the wire/conduit and may have sophisticated fiber-optic tapping equipment (which can tap a fiber without cutting it).
- I can physically inspect the conduit/cable/wire once a month.
- Ideally, the system would also notify me of a majority of successful attacks (or, even better, disconnect the line).
Okay, my $0.02 will likely cost you a large amount of money; but hey... if the data's so important to require self-destruct devices then I can understand that money isn't the biggest concern. Perhaps some of my ideas will prove useful.
Some of the previous articles mention using vacuum or pressure. This isn't a bad idea; though it could potentially be defeated by extremely carefully poking a small hole (about 5 microns in diameter) and then getting a pressure monitor on there. It may take hours for the gauge to read anything of use; but supposedly attackers may have that long. The hole itself would just look like a very small leak on 200 foot of pipe--and so you would believe that it's not an attacker.
Instead, you really should use a multi-layered configuration. Start with a fiber--they are a pain to tap without splicing; and I'll assume you could monitor each end and check for signal degradation that would be indicative of a splice. Then, the fiber should be insulated already, so jacket it in copper or aluminum sheeting (like grounded CAT5) with insulation on top of that. To top off the internal layer, send this "wire" down the smallest metal tube you can; with Great Stuff or other spray-in insulator filling the gap. Note that the fiber et al should be running nearly down the center of this conduit.
That's the first layer. Outside of that, fit the conduit inside another one (again, metal)--this one should be have a good vacuum on it. 10e-3 torr is easy to reach with a roughing pump, so you shouldn't have any trouble getting there. And then one more pipe outside of that. The final pipe should have a high pressure on it, 75 or 100 psi can be reached by a common air compressor. So this gives a total of three metal conduits to go through before reaching the fiber. Obviously, monitor the pressure from both ends--and those numbers should match up (with some error).
Yes, I realize this seems like over-kill. But, with this set up you can do some really cool things to check for intrusion. First, one can put different voltages across each of the 4 metal layers (fiber jacket included). If any of those are the same, you've got an attacker. You also can connect two layers on one end and gauge the resistance from the other. If this number doesn't match what it was yesterday, then there is an attacker. My personal favorite, though, is checking the capacitance between the different layers. If someone somehow figures out how to cut through the pressure and vacuum jacketting, the resistance test might be able to catch it. If you check the capacitance, there's almost no way they can not be detected. If this were me, I would configure both sides to randomly check different combinations from my list.
Finally, you likely will have a few seconds from when an attacker is detected and when he/she could be possibly be listening. This means that you can fully trust the computer on the other end even just after an intruder detection. Use this time for "Oh my God! Cut the line! Shut up and don't talk again!!!" as well as any other last-second transactions you need.
Long, cute, or funny Sigs are just another form of over compensation, used by geeks, nerdz, etc.
What if he's the one trying to break in to an already existing setup and is just looking for ideas on what kinds of defenses he might encounter?
I see even classic Slashdot is now pretty much unusable on dial up anymore.
True, under a lot of pressure, but it seems the media has totally forgotten about him. Luckily he probably won't run for reelection.
Oh, Conduit. I have nothing to say about that.
Where are we going and why am I in this handbasket?
Just a suggestion to add to a lot of other very adequate ideas...
I notice most of them recommend running fiber through some sort of pressurized, protected conduit, with various tamper notification schemes. Great; do all that. But instead of just running your single fiber strand, run a lot of them. If you feel extra devious, rig up something to pump garbage signal through them, signal which will look not unlike the encrypted traffic I assume you'll be using on the real line.
Stuff enough of them in there, and make the bogus signal convincing enough, and it will easily take your attacker longer than your one-month inspection period to breach the conduit, defeat the anti-tamper, and identify the correct strand, let alone get anything useful off it.
No relation to Happy Monkey
ignore all the comments about high pressure and other crap. pressure systems need to be maintained continously and are prone to failure.
Try this :
put a bunch of fibre optic strands into a steel pipe (large). make sure the fibre is all loose strands of single mode fibre (glass) and not encased in a protective coating. then fill the pipe completely with concrete and let it dry. attach the fibre to the terminal and the server and run something to monitor the connection 24/7. if the bad guys blowtorch thru the steel pipe they need to use a hammer to get thru the concrete. cracking the concrete cracks the fibre along with it destroying your connection (even if it is temporary and they rig something up to restore the connection your software monitoring the connection can sound the alarm). since single mode fibre is essentially very thin glass strands you will loose a few strands while pouring the concrete but at least one will work. you can use the one that works.
its messy but reliable. epoxy and other nasty stuff in layers with the concrete is also useful.