In case anyone else is as daft as I was, this will not work for everyone in an everybody-wears-headphones environment.
Quietnet: Chat client that works over near-ultrasonic sound
21–30 of 66 posts
Re: Quietnet: Chat client that works over near-ultrasonic sound
#22New computer security system: owning a dog
Re: Quietnet: Chat client that works over near-ultrasonic sound
#23Has anyone tried using this around their dogs?
I don't want to dos my puppy. :(
Re: Quietnet: Chat client that works over near-ultrasonic sound
#24ALSA lib pcm.c:2217:(snd_pcm_open_noupdate) Unknown PCM cards.pcm.rear
ALSA lib pcm.c:2217:(snd_pcm_open_noupdate) Unknown PCM cards.pcm.center_lfe
ALSA lib pcm.c:2217:(snd_pcm_open_noupdate) Unknown PCM cards.pcm.side
bt_audio_service_open: connect() failed: Connection refused (111)
bt_audio_service_open: connect() failed: Connection refused (111)
bt_audio_service_open: connect() failed: Connection refused (111)
bt_audio_service_open: connect() failed: Connection refused (111)
ALSA lib pcm_dmix.c:957:(snd_pcm_dmix_open) The dmix plugin supports only playback stream
Cannot connect to server socket err = No such file or directory
Cannot connect to server request channel
jack server is not running or cannot be started
Anyone else got this?
Re: Quietnet: Chat client that works over near-ultrasonic sound
#25Earlier quoted context omitted.
I would suspect those environments to be much too noisy for that to work.
Unless it's noisy at or near the desired communication frequency, it is trivial to isolate the signal and completely mute out the noise. In this example, at ~19 kHz, a properly configured high-pass filter could easily remove any human-talking sounds.
I'm not worried about humans talking, I'm worried about the ambient noise of the train/plane itself.
Re: Quietnet: Chat client that works over near-ultrasonic sound
#26Just installed and tried all the necessary packages, but for some reason it simply doesn't work. Here's a screenshot: http://cl.ly/image/180b0k3X332g I'm using a retina macbook pro 15 inches
Tried again, this time I get an 'o'. http://cl.ly/image/0e1A2c2i1Y16
I have a 13in Macbook Pro and the internal speakers were not working for me. However, I plugged in my higher quality headphones and held them up to the speaker and it worked. It might work if you plugged in external speakers.
Re: Quietnet: Chat client that works over near-ultrasonic sound
#27I'm glad people are realizing that radio waves aren't the only ways to send signals around a room. I really want someone to make a wireless, powerless keyboard where every key's click is tuned to a slightly different sound. Keylogging by acoustic emanations is a well researched technique, I just think it could be a feature if we made the keyboard right. https://www.schneier.com/blog/archives/2005/09/snooping_on_t...
Until you get crumbs under the keys... EDIT: "a wireless, powerless keyboard where every key's click is tuned to a slightly different sound" hang on, like a piano?
I think tones in our hearing range would be a bad idea. From what I remember of my music theory class, our brains (through either nature or nurture) don't like discordant sounds like that for a long time. In fact, I believe it's been used as a torture device in the past, although I'm guessing it wasn't just a weird jumble of notes in that case.
I don't think I'd be very good at programming in any case.
Re: Quietnet: Chat client that works over near-ultrasonic sound
#28I'm glad people are realizing that radio waves aren't the only ways to send signals around a room. I really want someone to make a wireless, powerless keyboard where every key's click is tuned to a slightly different sound. Keylogging by acoustic emanations is a well researched technique, I just think it could be a feature if we made the keyboard right. https://www.schneier.com/blog/archives/2005/09/snooping_on_t...
Interestingly, some early wireless TV remotes used sound this way. The battery-free remotes would strike a tone when a button was pressed, and carefully tuned forks in the TV set would resonate in response, triggering the remote function. http://www.tvhistory.tv/1957_Zentih_Ad-Remote1.JPG
There are also reasons they stopped using it in the first place[1]:
Some problems with this method were that the receiver could be triggered accidentally by naturally occurring noises, and some people could hear the piercing ultrasonic signals. There was an incident in which a toy xylophone changed the channels on such sets because some of the overtones from the xylophone matched the remote's ultrasonic frequency.
While each specific problem could be worked around with modern methods, it looks like a technique reserved for situations where you don't have a better option.
[1] http://en.wikipedia.org/wiki/Remote_control#Television_remot...
Re: Quietnet: Chat client that works over near-ultrasonic sound
#29Earlier quoted context omitted.
Until you get crumbs under the keys... EDIT: "a wireless, powerless keyboard where every key's click is tuned to a slightly different sound" hang on, like a piano?
I think tones in our hearing range would be a bad idea. From what I remember of my music theory class, our brains (through either nature or nurture) don't like discordant sounds like that for a long time. In fact, I believe it's been used as a torture device in the past, although I'm guessing it wasn't just a weird jumble of notes in that case. I don't think I'd be very good at programming in any case.
Click noises have no real tone character so could probably work. My keyboard already makes those anyway.
Re: Quietnet: Chat client that works over near-ultrasonic sound
#30Interesting... I thought the consensus was that these sounds weren't possible to create / detect on typical hardware according to recent discussions about mystery malware spreading through the air? I wonder what percentage of systems would be up to the required specs.
Malware can't spread via ultrasound, but it could certainly communicate via ultrasound. To spread would require that a sound picked up by the microphone would be executable, and in general, that can't happen. (In specific it can, of course; one could build a program to execute things from the microphone on purpose. But generally microphones do not get their input executed, and any hardware that did that would be incredibly, insanely broken. Mind you, I'm not saying that doesn't exist... just that it would be incredibly, insanely broken. Even by the standards of embedded hardware programming.)
Also, I don't think the badBIOS guy claimed it was spreading via ultrasound, that was sort of a generalized misinterpretation in the community.