4 ms·

I'd wager they've a dinky device that snaps onto a fibre (once it's unshielded), bends it a few degrees just enough that it leaks light ever so slightly, and ha

by madaxe 13y ago

I'd wager they've a dinky device that snaps onto a fibre (once it's unshielded), bends it a few degrees just enough that it leaks light ever so slightly, and have a photodiode within the device to amplify and relay the intercepted light down a parasite.

beloch 13y ago
Ah... You sound like you know a bit! This method does indeed sound easier to pull off. Do you know how much loss you'd have to create before the fiber was bent enough to provide sufficient signal to the photodiode?
ceph_ 13y ago
I assume you're referring to the shielding seen here. http://patentimages.storage.googleapis.com/pages/US4974926-1.png http://patentimages.storage.googleapis.com/pages/US4974926-1... There's no way you're getting through that without it being service affecting. Even once you get through the layers of protective sheathing, and around the copper power lines that provide power to the undersea amps, you're suggesting that they fully remove the reflective sheathing to bend the fiber and tap off light? That is absolutely ludicrous. The process would introduce much more span attenuation than splicing in a 50/50 fiber tap (which is 3db). Are you doing this to every fiber in the bundle, you'll need at least two tapped to get bi-directional communication. It's simply unfeasible.
- BrandonMarc 13y ago
  > It's simply unfeasible. The NSA loves when people think this thought.
- madaxe 13y ago
  Alright, you tell me how you do it then.
xlevus 13y ago
I'd wager it's even simpler than that. At some point the signal must a) be converted from electrical to optical b) be boosted down the wire c) be converted from optical to electrical Easiest solution? Tap in at A, B or C. Who's going to notice that your repeater at the bottom of the ocean actually has a NSA listener plugged into its debug socket?
- marshray 13y ago
  No, actually in modern systems the light signal is boosted without an intermediate conversion to an electrical signal: http://en.wikipedia.org/wiki/Optical_amplifier http://en.wikipedia.org/wiki/Optical_amplifier
  - beloch 13y ago
    Some types of optical amplifiers are vulnerable to side channel attacks, so they might be a weak point. However, they're also probably under more scrutiny from both maintenance and security people.

by madaxe 13y ago

beloch 13y ago

Ah... You sound like you know a bit! This method does indeed sound easier to pull off. Do you know how much loss you'd have to create before the fiber was bent enough to provide sufficient signal to the photodiode?

ceph_ 13y ago

I assume you're referring to the shielding seen here. http://patentimages.storage.googleapis.com/pages/US4974926-1.png http://patentimages.storage.googleapis.com/pages/US4974926-1... There's no way you're getting through that without it being service affecting. Even once you get through the layers of protective sheathing, and around the copper power lines that provide power to the undersea amps, you're suggesting that they fully remove the reflective sheathing to bend the fiber and tap off light? That is absolutely ludicrous. The process would introduce much more span attenuation than splicing in a 50/50 fiber tap (which is 3db). Are you doing this to every fiber in the bundle, you'll need at least two tapped to get bi-directional communication. It's simply unfeasible.

BrandonMarc 13y ago
> It's simply unfeasible. The NSA loves when people think this thought.
madaxe 13y ago
Alright, you tell me how you do it then.

xlevus 13y ago

I'd wager it's even simpler than that. At some point the signal must a) be converted from electrical to optical b) be boosted down the wire c) be converted from optical to electrical Easiest solution? Tap in at A, B or C. Who's going to notice that your repeater at the bottom of the ocean actually has a NSA listener plugged into its debug socket?

marshray 13y ago
No, actually in modern systems the light signal is boosted without an intermediate conversion to an electrical signal: http://en.wikipedia.org/wiki/Optical_amplifier http://en.wikipedia.org/wiki/Optical_amplifier
- beloch 13y ago
  Some types of optical amplifiers are vulnerable to side channel attacks, so they might be a weak point. However, they're also probably under more scrutiny from both maintenance and security people.