5 ms·

Why would not having shielding save copper? Shielding is usually made out of a metal foil or mesh, often aluminium. I've never seen shielding out of copper.

fisherjeff 9y ago
I think the copper savings in 1000BASE-T1 come from running GigE over a single pair versus the more-typical 4.
daniel-cussen 9y ago
The NSA (read money is no object) has copper in the windows of its main building to shield them from TEMPEST style hacking.
- marzell 9y ago
  These are 2 fundamentally different things. In twisted pairs, shielding is there to prevent interference from changing a signal. In TEMPEST protection systems, shielding is used to prevent radiance of transmissions that could be intercepted. While there is some overlap in conductive materials that could do both (prevent interference AND radiance), the methods employed and benchmarks used to measure performance differ significantly.
- azinman2 9y ago
  Sounds like money well spent
  - SCHiM 9y ago
    It is actually. I've seen hazy images recovered from your monitor by collecting the radio emissions of the cable. The signal traveled through windows, walls and an airgap of about 15 meters. The antenna used in that attack was only about half a meter long I think. I imagine you could put a much bigger antenna (or a dish) inside a van in the parking lot and spy on some analysts or something...
    - consp 9y ago
      It's possible to collect it from status leds for instance: http://www.applied-math.org/optical_tempest.pdf http://www.applied-math.org/optical_tempest.pdf
      - StavrosK 9y ago
        Jeez, at this point we might as well assume you can collect information from anything. I bet someone has made something that can restore the image on your screen by the vibrations on the windows that the sound of the power supply makes as the data flows in.
    - Bartweiss 9y ago
      A good-sized antenna at range works, and so does a tiny device at close range! There are Van Eck listeners small enough to conceal completely that can still eavesdrop table-to-table at a cafe. The conference debut involved hiding one in a piece of pita bread, where it could sit right out in the open. https://t2.fi/tag/van-eck-phreaking/ https://t2.fi/tag/van-eck-phreaking/

fisherjeff 9y ago

I think the copper savings in 1000BASE-T1 come from running GigE over a single pair versus the more-typical 4.

daniel-cussen 9y ago

The NSA (read money is no object) has copper in the windows of its main building to shield them from TEMPEST style hacking.

marzell 9y ago
These are 2 fundamentally different things. In twisted pairs, shielding is there to prevent interference from changing a signal. In TEMPEST protection systems, shielding is used to prevent radiance of transmissions that could be intercepted. While there is some overlap in conductive materials that could do both (prevent interference AND radiance), the methods employed and benchmarks used to measure performance differ significantly.
azinman2 9y ago
Sounds like money well spent
- SCHiM 9y ago
  It is actually. I've seen hazy images recovered from your monitor by collecting the radio emissions of the cable. The signal traveled through windows, walls and an airgap of about 15 meters. The antenna used in that attack was only about half a meter long I think. I imagine you could put a much bigger antenna (or a dish) inside a van in the parking lot and spy on some analysts or something...
  - consp 9y ago
    It's possible to collect it from status leds for instance: http://www.applied-math.org/optical_tempest.pdf http://www.applied-math.org/optical_tempest.pdf
    - StavrosK 9y ago
      Jeez, at this point we might as well assume you can collect information from anything. I bet someone has made something that can restore the image on your screen by the vibrations on the windows that the sound of the power supply makes as the data flows in.
  - Bartweiss 9y ago
    A good-sized antenna at range works, and so does a tiny device at close range! There are Van Eck listeners small enough to conceal completely that can still eavesdrop table-to-table at a cafe. The conference debut involved hiding one in a piece of pita bread, where it could sit right out in the open. https://t2.fi/tag/van-eck-phreaking/ https://t2.fi/tag/van-eck-phreaking/