5 ms·

> Earlier discussion: https://news.ycombinator.com/item?id=34423395 https://news.ycombinator.com/item?id=34423395 The top comment [0] on this has: > Counter-m

> Earlier discussion: https://news.ycombinator.com/item?id=34423395 https://news.ycombinator.com/item?id=34423395 The top comment [0] on this has: > Counter-measures: https://news.ycombinator.com/item?id=27121918#27133079 https://news.ycombinator.com/item?id=27121918#27133079 but I don't understand the setup here. If you have the capability to run custom firmware on your router then don't you not need this countermeasure, since you can be confident your router isn't doing this wireframing anyway? Or is it saying that a passive bystander who is not connected to your network can infer the wireframes as well? That seems unlikely to me? [0]: https://news.ycombinator.com/item?id=34424242 https://news.ycombinator.com/item?id=34424242

deleted 4y ago
[deleted]
transpute 4y ago
> passive bystander who is not connected to your network can infer the wireframes as well? Yes, this can be done with a custom client monitoring existing routers today. A bystander can also use their own router (2.4Ghz passes through most walls) to make inferences about human activity inside your building.
- arkadiyt 4y ago
  Then the countermeasure does nothing since you can't run your firmware on their router?
  - avree 4y ago
    Correct, this 'countermeasure' is for a fantasy world in which it's easier to compromise your router than set up a couple clients and a router nearby. Also, realistically, wi-fi isn't the boogeyman here, even though the person you're replying to has been doom-posting about it for years - UWB and various other tech is going to make detecting location and movement from RF frequency fairly trivial.
    - transpute 4y ago
      > compromise your router No compromise needed. This was one research project looking at the current world where your existing router is happily beaming location information out of your home, which can be read by an attacker with a passive receiver. If an attacker is forced to use their own transmitter, that can potentially be detected. > wi-fi isn't the bogeyman here Wi-Fi is the lowest cost modern application of ancient doppler imaging radar that has been around for decades. There is code for ESP32 devices, https://wrlab.github.io/Wi-ESP/ https://wrlab.github.io/Wi-ESP/. Many years ago, through-the-wall surveillance was primarily used by military and law enforcement with devices costing thousands of dollars. How many people are aware that the capability is now available for $20?
  - transpute 4y ago
    This was just one tiny EU research project with limited funding, which was focused only on passive attacks, e.g. a receiver with custom firmware can make inferences from existing Wi-Fi routers. Their research was looking for a way to modify the default behavior of Wi-Fi transmitters to reduce leakage of location information. If this was the default behavior (e.g. via some combination of IEEE standard and regulation), then active attackers could be easily identified. https://ans.unibs.it/projects/csi-murder/ https://ans.unibs.it/projects/csi-murder/ > this paper addressed passive attacks, where the attacker controls only a receiver, but exploits the normal Wi-Fi traffic. In this case, the only useful traffic for the attacker comes from transmitters that are perfectly fixed and whose position is well known and stable, so that the NN can be trained in advance, thus the obfuscator needs to be installed only in APs or similar ‘infrastructure’ devices. Active attacks, where the attacker controls both the transmitter and the receiver are another very interesting research area, where, however, privacy protection cannot be based on randomization at the transmitter. More research and funding is needed.
- d1sxeyes 4y ago
  I'm not sure that's accurate. The article suggests they used three routers, and mention 'interference'. I think you'd perhaps need to be more than a 'bystander' to be able to set up a triangle of WiFi routers around someone's home. Not impossible, of course, but by that point, no longer really a 'bystander'.
  - transpute 4y ago
    Depends on the adversary's objective. The DensePose paper is only one of hundreds of papers on Wi-Fi Sensing for different activities, over ~10 years of funded research, https://news.ycombinator.com/item?id=34485816 https://news.ycombinator.com/item?id=34485816. E.g. keystroke recognition can be done with a single passive receiver, https://news.ycombinator.com/item?id=34485613 https://news.ycombinator.com/item?id=34485613 Some research is less dependent on the training environment, https://techxplore.com/news/2021-11-winect-tracks-3d-human-poses.html https://techxplore.com/news/2021-11-winect-tracks-3d-human-p... > wireless sensing systems .. mostly rely on models that were pre-trained on a fixed set of known activities, thus they can only classify a limited number of human poses or movements .. our system uses signal processing techniques to separate the Wi-Fi signals reflected from each moving limb and track the trajectory of each limb .. Winect could track free-form human activities with centimeter-level accuracy in a variety of challenging environments and scenarios. Dec 2022 survey paper categorized recent research on wireless device-free human sensing, https://dl.acm.org/doi/10.1145/3530682 https://dl.acm.org/doi/10.1145/3530682 > WDHS systems involve three primary sensing task types. The first type, behavior recognition .. second type is movement tracking .. The third type, user identification, leverages the unique features in behaviors to identify who performs the movements .. we believe that more context-aware multi-modal systems will be proposed to handle the complex sensing tasks in real life.
  - lwhi 4y ago
    I read it as three WiFi modules .. such as the three contained in the WIFI router mentioned.
    - d1sxeyes 4y ago
      Good shout. I checked the actual paper (here: https://arxiv.org/pdf/2301.00250.pdf https://arxiv.org/pdf/2301.00250.pdf, link in the article is broken), and seems you would need multiple routers: > [...] three WiFi transmitters and three aligned receivers [...]. It should be noted that many WiFi routers, such as TP-Link AC1750, come with 3 antennas, so our method only requires 2 of these routers. So basically, one on each side of the subject, one to transmit the signal, the other to receive, and then you can work out the interference pattern. It may be possible to do the same with the transmitters and receivers on the same physical device by measuring the reflected signal, but that doesn't seem to be what they were testing. It seems that the person needs to be between the transmitter and receiver, so I'm not even sure if triangulation would work, although figure 2 implies that you need the 'line of sight' between the routers to be blocked (three 'transmitter' routers and three 'receiver' routers).
rhn_mk1 4y ago
It seems that it's for installing on a station device I guess?
- Gare 4y ago
  Time to cover walls with tinfoil? :)
  - ivxvm 4y ago
    I've actually seen people doing this. I wish I had one too. In few decades we'll have Faradey chambers for rent on per hour basis, just like music studios nowadays.
    - transpute 4y ago
      For smaller rooms with good HVAC ventilation for fresh air, EMF reduction can be achieved with removable clamping ZipWall/FastCap poles to support grounded aluminum radiant barrier on walls, roof & floor. E.g. Attic Foil has white vinyl on one side and conductive foil on the other side, about $0.25/sq ft. Matching tape for joints. To frame the shielded room-within-a-room, cheaper alternatives to ZipWall/FastCap are PVC furniture pipe, electric metallic tube (EMT) conduit or 2x4 pine. Doorway can be shielded with radiant barrier and RE-U-ZIP magnetic entry strip for a reclosable opening. Bonus side effect is thermal insulation. Transparent RF shielding for windows is more expensive ($4/sq ft), https://safelivingtechnologies.com/signal-protect/ https://safelivingtechnologies.com/signal-protect/. Use air quality and EMF meters to validate the design and monitor ongoing effectiveness.
deleted 4y ago
[deleted]
ilyt 4y ago
> Or is it saying that a passive bystander who is not connected to your network can infer the wireframes as well? That seems unlikely to me? Also known as passive radar

deleted 4y ago

[deleted]

transpute 4y ago

> passive bystander who is not connected to your network can infer the wireframes as well? Yes, this can be done with a custom client monitoring existing routers today. A bystander can also use their own router (2.4Ghz passes through most walls) to make inferences about human activity inside your building.

arkadiyt 4y ago
Then the countermeasure does nothing since you can't run your firmware on their router?
- avree 4y ago
  Correct, this 'countermeasure' is for a fantasy world in which it's easier to compromise your router than set up a couple clients and a router nearby. Also, realistically, wi-fi isn't the boogeyman here, even though the person you're replying to has been doom-posting about it for years - UWB and various other tech is going to make detecting location and movement from RF frequency fairly trivial.
  - transpute 4y ago
    > compromise your router No compromise needed. This was one research project looking at the current world where your existing router is happily beaming location information out of your home, which can be read by an attacker with a passive receiver. If an attacker is forced to use their own transmitter, that can potentially be detected. > wi-fi isn't the bogeyman here Wi-Fi is the lowest cost modern application of ancient doppler imaging radar that has been around for decades. There is code for ESP32 devices, https://wrlab.github.io/Wi-ESP/ https://wrlab.github.io/Wi-ESP/. Many years ago, through-the-wall surveillance was primarily used by military and law enforcement with devices costing thousands of dollars. How many people are aware that the capability is now available for $20?
- transpute 4y ago
  This was just one tiny EU research project with limited funding, which was focused only on passive attacks, e.g. a receiver with custom firmware can make inferences from existing Wi-Fi routers. Their research was looking for a way to modify the default behavior of Wi-Fi transmitters to reduce leakage of location information. If this was the default behavior (e.g. via some combination of IEEE standard and regulation), then active attackers could be easily identified. https://ans.unibs.it/projects/csi-murder/ https://ans.unibs.it/projects/csi-murder/ > this paper addressed passive attacks, where the attacker controls only a receiver, but exploits the normal Wi-Fi traffic. In this case, the only useful traffic for the attacker comes from transmitters that are perfectly fixed and whose position is well known and stable, so that the NN can be trained in advance, thus the obfuscator needs to be installed only in APs or similar ‘infrastructure’ devices. Active attacks, where the attacker controls both the transmitter and the receiver are another very interesting research area, where, however, privacy protection cannot be based on randomization at the transmitter. More research and funding is needed.
d1sxeyes 4y ago
I'm not sure that's accurate. The article suggests they used three routers, and mention 'interference'. I think you'd perhaps need to be more than a 'bystander' to be able to set up a triangle of WiFi routers around someone's home. Not impossible, of course, but by that point, no longer really a 'bystander'.
- transpute 4y ago
  Depends on the adversary's objective. The DensePose paper is only one of hundreds of papers on Wi-Fi Sensing for different activities, over ~10 years of funded research, https://news.ycombinator.com/item?id=34485816 https://news.ycombinator.com/item?id=34485816. E.g. keystroke recognition can be done with a single passive receiver, https://news.ycombinator.com/item?id=34485613 https://news.ycombinator.com/item?id=34485613 Some research is less dependent on the training environment, https://techxplore.com/news/2021-11-winect-tracks-3d-human-poses.html https://techxplore.com/news/2021-11-winect-tracks-3d-human-p... > wireless sensing systems .. mostly rely on models that were pre-trained on a fixed set of known activities, thus they can only classify a limited number of human poses or movements .. our system uses signal processing techniques to separate the Wi-Fi signals reflected from each moving limb and track the trajectory of each limb .. Winect could track free-form human activities with centimeter-level accuracy in a variety of challenging environments and scenarios. Dec 2022 survey paper categorized recent research on wireless device-free human sensing, https://dl.acm.org/doi/10.1145/3530682 https://dl.acm.org/doi/10.1145/3530682 > WDHS systems involve three primary sensing task types. The first type, behavior recognition .. second type is movement tracking .. The third type, user identification, leverages the unique features in behaviors to identify who performs the movements .. we believe that more context-aware multi-modal systems will be proposed to handle the complex sensing tasks in real life.
- lwhi 4y ago
  I read it as three WiFi modules .. such as the three contained in the WIFI router mentioned.
  - d1sxeyes 4y ago
    Good shout. I checked the actual paper (here: https://arxiv.org/pdf/2301.00250.pdf https://arxiv.org/pdf/2301.00250.pdf, link in the article is broken), and seems you would need multiple routers: > [...] three WiFi transmitters and three aligned receivers [...]. It should be noted that many WiFi routers, such as TP-Link AC1750, come with 3 antennas, so our method only requires 2 of these routers. So basically, one on each side of the subject, one to transmit the signal, the other to receive, and then you can work out the interference pattern. It may be possible to do the same with the transmitters and receivers on the same physical device by measuring the reflected signal, but that doesn't seem to be what they were testing. It seems that the person needs to be between the transmitter and receiver, so I'm not even sure if triangulation would work, although figure 2 implies that you need the 'line of sight' between the routers to be blocked (three 'transmitter' routers and three 'receiver' routers).

rhn_mk1 4y ago

It seems that it's for installing on a station device I guess?

Gare 4y ago
Time to cover walls with tinfoil? :)
- ivxvm 4y ago
  I've actually seen people doing this. I wish I had one too. In few decades we'll have Faradey chambers for rent on per hour basis, just like music studios nowadays.
  - transpute 4y ago
    For smaller rooms with good HVAC ventilation for fresh air, EMF reduction can be achieved with removable clamping ZipWall/FastCap poles to support grounded aluminum radiant barrier on walls, roof & floor. E.g. Attic Foil has white vinyl on one side and conductive foil on the other side, about $0.25/sq ft. Matching tape for joints. To frame the shielded room-within-a-room, cheaper alternatives to ZipWall/FastCap are PVC furniture pipe, electric metallic tube (EMT) conduit or 2x4 pine. Doorway can be shielded with radiant barrier and RE-U-ZIP magnetic entry strip for a reclosable opening. Bonus side effect is thermal insulation. Transparent RF shielding for windows is more expensive ($4/sq ft), https://safelivingtechnologies.com/signal-protect/ https://safelivingtechnologies.com/signal-protect/. Use air quality and EMF meters to validate the design and monitor ongoing effectiveness.

deleted 4y ago

[deleted]

ilyt 4y ago

> Or is it saying that a passive bystander who is not connected to your network can infer the wireframes as well? That seems unlikely to me? Also known as passive radar