5 ms·

If the authorities sought to disrupt these networks, would it not be possible to jam Bluetooth (and Wi-Fi) signals within a certain area?

by Zirro 12y ago

ISL 12y ago
It would have collateral effects (disabling all wireless activity in the area of jamming), but it's absolutely possible.
- wyager 12y ago
  >disabling all wireless activity in the area of jamming Only on the jammed frequencies. Police radios and such will keep working.
  - sliverstorm 12y ago
    Weeelll... that depends on a lot of things. Any jammer with the power to work over a meaningful radius in this context is probably going to throw out lots of spurious emissions in neighboring bands.
    - jMyles 12y ago
      Police Radios (and GMRS, and FRS) are not neighboring bands to 802.11
      - reckoner13 12y ago
        Does China use the same frequency bands as US?
        jMyles 12y ago
        Looking at this document (http://www.ncc.gov.tw/english/files/07060/92_070605_1.pdf http://www.ncc.gov.tw/english/files/07060/92_070605_1.pdf) it's not immediately clear. A ctrl-F for "emergency" and "police" yields no results. However, there is a FRS band which is the same as the US. Moreover, the bands used by "push-to-talk" radios are ones that transmit reasonably far for lowish power and penetrate walls. No reason to think they'll be different worldwide.
        taejo 12y ago
        That document is about the Republic of China (Taiwan), not about Hong Kong or the People's Republic of China.
  - McDoku 12y ago
    I think he was talking about the surrounding businesses. Jamming or interference with business operations might provoke a flight of capital. Hong Kong is rather concentrated.
    - tkinom 12y ago
      The police can blame the protesters for all the troubles - block traffic, stopping commerce, blocking cell/wifi/BT service. From what I read, not much different than the police strategy used the 99% protest in Wall Street.
      - McDoku 12y ago
        I don't recall the US banning twitter or censoring any social network. No prohibition of coverage. Not to mention there was a tremendous amount of sympathetic coverage. Time 2011 person of the year was the protester. It was a huge conversation that entered the common narrative. Apples and Oranges. Yeah, there are best practices for dealing with crowds and there needs to be security at huge protests. The cloak and the shield is a very fine line. I know for a fact in Canada there was no wifi/cell/BT blocking. And I cannot find a reputable article the provides any evidence that this occurred.
        pmorici 12y ago
        He is saying that they blamed the protestors for inconveniences caused by police actions not that the police in the US blocked cell service. The strategy for dealing with the protests in the US was just to wait them out and then when the media got bored they sent in the police to clear out the camps while people weren't paying attention.
        McDoku 12y ago
        I think he was saying all of the above, but I am not sure any of the strategies he mentioned will work in Hong Kong.
xnull 12y ago
100% possible and at reasonably low cost.
pshc 12y ago
Authorities could also produce rogue clients that spam malicious messages--depends how resilient FireChat's protocol is and how well it filters noise (I might be talking FUD though as I haven't tried it). Moreover, there's no way to police bad actors in a local mesh, and no global blockchain you can trust.
- cik 12y ago
  I've been wondering about exactly this - the agreed upon blockchain problem. Why not localized meshnets based on Hyperboria (http://hyperboria.net/ http://hyperboria.net/). It can solve the problems of trusted blockchain - but you still have the social problem of interloper.
ryan-allen 12y ago
I don't see why not, they're already conducting aggressive SIGINT operations against it's own citizens!
matznerd 12y ago
yes it's not very hard to jam, there are many jammers available online, a top result in a quick search was ironically from a site called jammerfromchina.com...[1] Also, with an alfa wireless card and python (scapy module) it can be done pretty easily [2]. [1] http://www.jammerfromchina.com/categories/WiFi%7B47%7DBluetooth_Jammers/ http://www.jammerfromchina.com/categories/WiFi%7B47%7DBlueto... [2] https://github.com/DanMcInerney/wifijammer https://github.com/DanMcInerney/wifijammer
- visarga 12y ago
  Can light be used to send messages when wi-fi is jammed? I mean modulating the torchlight and using cams. I realize this would be very low bandwidth though...
  - dlubarov 12y ago
    Well, radio waves consist of light, albeit outside of the visible spectrum. It is certainly possible to transmit signals using visible light (see Li-Fi), although visible light transmissions could be jammed using the same techniques. Might not be ideal for covert communication though, since you could see someone broadcasting without any special equipment.
  - hobs 12y ago
    Laser point to point: http://www.extremetech.com/extreme/128207-1gbps-wireless-network-made-with-red-and-green-laser-pointers http://www.extremetech.com/extreme/128207-1gbps-wireless-net... This is not low bandwidth if you have the right tools.
  - nitrogen 12y ago
    PDAs used to have IRDA ports for exactly that.
spacefight 12y ago
I'm 100% sure they will. It's just a learning process on the gov side, kicked of by recent events.
morsch 12y ago
The next step would be exchanging messages via NFC. E.g. say for a p2p-twitter app, users A and B go into the exchange with their own versions of the global p2p-twitter feed, and exit the exchange with a merged version. You could do federated, store-and-forward direct messaging, too. We already have a protocol for a very similar use-case: SMTP. :) Of course, with a sometimes-offline P2P mesh you usually don't know if any given hop decreases the distance to the destination. You'd probably end up just merging all existing messages, so that everyone has everyone elses "email", and filter out the messages belonging to you via asymmetric encryption. So it's just an application of the above p2p-twitter thing. Public messages could be unencrypted. I think some blockchain-based messaging systems work in a similar way, since there everybody has everybody elses messages per definition. Maybe a blockchain-based protocol is a good fit anyway, probably not though since I'm not sure how it would do the merge(A,B) function.
- lifeisstillgood 12y ago
  I absolutely love that idea !
- nitrogen 12y ago
  There were also systems designed for the BBS days that expected to have zero connectivity most of the time. They would dial other computers periodically and exchange data. e.g. http://en.wikipedia.org/wiki/FidoNet http://en.wikipedia.org/wiki/FidoNet

If the authorities sought to disrupt these networks, would it not be possible to jam Bluetooth (and Wi-Fi) signals within a certain area?

by Zirro 12y ago

If the authorities sought to disrupt these networks, would it not be possible to jam Bluetooth (and Wi-Fi) signals within a certain area?

ISL 12y ago

It would have collateral effects (disabling all wireless activity in the area of jamming), but it's absolutely possible.

wyager 12y ago
>disabling all wireless activity in the area of jamming Only on the jammed frequencies. Police radios and such will keep working.
- sliverstorm 12y ago
  Weeelll... that depends on a lot of things. Any jammer with the power to work over a meaningful radius in this context is probably going to throw out lots of spurious emissions in neighboring bands.
  - jMyles 12y ago
    Police Radios (and GMRS, and FRS) are not neighboring bands to 802.11
    - reckoner13 12y ago
      Does China use the same frequency bands as US?
      - jMyles 12y ago
        Looking at this document (http://www.ncc.gov.tw/english/files/07060/92_070605_1.pdf http://www.ncc.gov.tw/english/files/07060/92_070605_1.pdf) it's not immediately clear. A ctrl-F for "emergency" and "police" yields no results. However, there is a FRS band which is the same as the US. Moreover, the bands used by "push-to-talk" radios are ones that transmit reasonably far for lowish power and penetrate walls. No reason to think they'll be different worldwide.
        taejo 12y ago
        That document is about the Republic of China (Taiwan), not about Hong Kong or the People's Republic of China.
- McDoku 12y ago
  I think he was talking about the surrounding businesses. Jamming or interference with business operations might provoke a flight of capital. Hong Kong is rather concentrated.
  - tkinom 12y ago
    The police can blame the protesters for all the troubles - block traffic, stopping commerce, blocking cell/wifi/BT service. From what I read, not much different than the police strategy used the 99% protest in Wall Street.
    - McDoku 12y ago
      I don't recall the US banning twitter or censoring any social network. No prohibition of coverage. Not to mention there was a tremendous amount of sympathetic coverage. Time 2011 person of the year was the protester. It was a huge conversation that entered the common narrative. Apples and Oranges. Yeah, there are best practices for dealing with crowds and there needs to be security at huge protests. The cloak and the shield is a very fine line. I know for a fact in Canada there was no wifi/cell/BT blocking. And I cannot find a reputable article the provides any evidence that this occurred.
      - pmorici 12y ago
        He is saying that they blamed the protestors for inconveniences caused by police actions not that the police in the US blocked cell service. The strategy for dealing with the protests in the US was just to wait them out and then when the media got bored they sent in the police to clear out the camps while people weren't paying attention.
        McDoku 12y ago
        I think he was saying all of the above, but I am not sure any of the strategies he mentioned will work in Hong Kong.

xnull 12y ago

100% possible and at reasonably low cost.

pshc 12y ago

Authorities could also produce rogue clients that spam malicious messages--depends how resilient FireChat's protocol is and how well it filters noise (I might be talking FUD though as I haven't tried it). Moreover, there's no way to police bad actors in a local mesh, and no global blockchain you can trust.

cik 12y ago
I've been wondering about exactly this - the agreed upon blockchain problem. Why not localized meshnets based on Hyperboria (http://hyperboria.net/ http://hyperboria.net/). It can solve the problems of trusted blockchain - but you still have the social problem of interloper.

ryan-allen 12y ago

I don't see why not, they're already conducting aggressive SIGINT operations against it's own citizens!

matznerd 12y ago

yes it's not very hard to jam, there are many jammers available online, a top result in a quick search was ironically from a site called jammerfromchina.com...[1] Also, with an alfa wireless card and python (scapy module) it can be done pretty easily [2]. [1] http://www.jammerfromchina.com/categories/WiFi%7B47%7DBluetooth_Jammers/ http://www.jammerfromchina.com/categories/WiFi%7B47%7DBlueto... [2] https://github.com/DanMcInerney/wifijammer https://github.com/DanMcInerney/wifijammer

visarga 12y ago
Can light be used to send messages when wi-fi is jammed? I mean modulating the torchlight and using cams. I realize this would be very low bandwidth though...
- dlubarov 12y ago
  Well, radio waves consist of light, albeit outside of the visible spectrum. It is certainly possible to transmit signals using visible light (see Li-Fi), although visible light transmissions could be jammed using the same techniques. Might not be ideal for covert communication though, since you could see someone broadcasting without any special equipment.
- hobs 12y ago
  Laser point to point: http://www.extremetech.com/extreme/128207-1gbps-wireless-network-made-with-red-and-green-laser-pointers http://www.extremetech.com/extreme/128207-1gbps-wireless-net... This is not low bandwidth if you have the right tools.
- nitrogen 12y ago
  PDAs used to have IRDA ports for exactly that.

spacefight 12y ago

I'm 100% sure they will. It's just a learning process on the gov side, kicked of by recent events.

morsch 12y ago

The next step would be exchanging messages via NFC. E.g. say for a p2p-twitter app, users A and B go into the exchange with their own versions of the global p2p-twitter feed, and exit the exchange with a merged version. You could do federated, store-and-forward direct messaging, too. We already have a protocol for a very similar use-case: SMTP. :) Of course, with a sometimes-offline P2P mesh you usually don't know if any given hop decreases the distance to the destination. You'd probably end up just merging all existing messages, so that everyone has everyone elses "email", and filter out the messages belonging to you via asymmetric encryption. So it's just an application of the above p2p-twitter thing. Public messages could be unencrypted. I think some blockchain-based messaging systems work in a similar way, since there everybody has everybody elses messages per definition. Maybe a blockchain-based protocol is a good fit anyway, probably not though since I'm not sure how it would do the merge(A,B) function.

lifeisstillgood 12y ago
I absolutely love that idea !
nitrogen 12y ago
There were also systems designed for the BBS days that expected to have zero connectivity most of the time. They would dial other computers periodically and exchange data. e.g. http://en.wikipedia.org/wiki/FidoNet http://en.wikipedia.org/wiki/FidoNet