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Support for a TEMPEST mode of communication would be a killer feature. Perhaps vibrate mode on one phone being picked up by the accelerometer of another? In o

Support for a TEMPEST mode of communication would be a killer feature. Perhaps vibrate mode on one phone being picked up by the accelerometer of another? In our hypothetical dystopian future The Regime will probably jam 2Ghz to 5Ghz in public spaces. TEMPEST mode would also force them to install vibrators into all coffee shop tables.

ed25519FUUU 6y ago
What’s TEMPEST? Something that communicates by vibrating a table? In my dystopian future theory, the government that has no issue jamming 2 and 5 ghz channels to keep people from talking would probably notice two people on on a table continually picking up And dropping their phones. Why wouldn’t they simply whisper to each other in that scenario?
- gorgoiler 6y ago
  TEMPEST is a generic term for extracting data that emanates from channels which were are not supposed to carry data. It’s usually an attack, used to spy on people. The classic example is pointing a high speed camera at an office window across the street and recording the brightness of the walls. Even if the office computer is hidden out of sight the attacker can reconstruct what’s on screen by analysing subtle changes in brightness reflected off the wall.
  - riobard 6y ago
    > The classic example is pointing a high speed camera at an office window across the street and recording the brightness of the walls. Even if the office computer is hidden out of sight the attacker can reconstruct what’s on screen by analysing subtle changes in brightness reflected off the wall. Is this feasible now?
    - Xophmeister 6y ago
      Yep https://www.nassiben.com/lamphone https://www.nassiben.com/lamphone
    - namibj 6y ago
      That was specific for CRTs. You can still exploit diffuse reflections, though that's much harder.
  - maqp 6y ago
    The more classic example is display cables like VGA, DVI and HDMI emanate signals that can be used to reconstruct the image displayed. Doesn't work for newer high speed HDMI though. Old BBC documentary on the topic https://www.youtube.com/watch?v=mcV6izFG3vQ https://www.youtube.com/watch?v=mcV6izFG3vQ
eeZah7Ux 6y ago
> Support for a TEMPEST mode of communication would be a killer feature. You are misusing the term. TEMPEST is an attack. > Perhaps vibrate mode on one phone being picked up by the accelerometer of another? At very close distance vibrating our vocal cords and eardrums would be much easier and works without battery.
- Forbo 6y ago
  I can't exactly modulate my vocal chords to send a file. But I think you're right, using some sort of high-frequency beacon tone like what they use for the creeping tracking identifiers might be an option.

ed25519FUUU 6y ago

What’s TEMPEST? Something that communicates by vibrating a table? In my dystopian future theory, the government that has no issue jamming 2 and 5 ghz channels to keep people from talking would probably notice two people on on a table continually picking up And dropping their phones. Why wouldn’t they simply whisper to each other in that scenario?

gorgoiler 6y ago
TEMPEST is a generic term for extracting data that emanates from channels which were are not supposed to carry data. It’s usually an attack, used to spy on people. The classic example is pointing a high speed camera at an office window across the street and recording the brightness of the walls. Even if the office computer is hidden out of sight the attacker can reconstruct what’s on screen by analysing subtle changes in brightness reflected off the wall.
- riobard 6y ago
  > The classic example is pointing a high speed camera at an office window across the street and recording the brightness of the walls. Even if the office computer is hidden out of sight the attacker can reconstruct what’s on screen by analysing subtle changes in brightness reflected off the wall. Is this feasible now?
  - Xophmeister 6y ago
    Yep https://www.nassiben.com/lamphone https://www.nassiben.com/lamphone
  - namibj 6y ago
    That was specific for CRTs. You can still exploit diffuse reflections, though that's much harder.
- maqp 6y ago
  The more classic example is display cables like VGA, DVI and HDMI emanate signals that can be used to reconstruct the image displayed. Doesn't work for newer high speed HDMI though. Old BBC documentary on the topic https://www.youtube.com/watch?v=mcV6izFG3vQ https://www.youtube.com/watch?v=mcV6izFG3vQ

eeZah7Ux 6y ago

> Support for a TEMPEST mode of communication would be a killer feature. You are misusing the term. TEMPEST is an attack. > Perhaps vibrate mode on one phone being picked up by the accelerometer of another? At very close distance vibrating our vocal cords and eardrums would be much easier and works without battery.

Forbo 6y ago
I can't exactly modulate my vocal chords to send a file. But I think you're right, using some sort of high-frequency beacon tone like what they use for the creeping tracking identifiers might be an option.