Quietnet: Chat client that works over near-ultrasonic sound
1–10 of 66 posts
Re: Quietnet: Chat client that works over near-ultrasonic sound
#2I'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...
Re: Quietnet: Chat client that works over near-ultrasonic sound
#3Interesting... 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.
Re: Quietnet: Chat client that works over near-ultrasonic sound
#4It looks like it would interoperate with standard amateur radio PSK-31 software if you set the ham radio software to 19043 Hz (instead of more typical 500-2000 or so Hz)
Over the last 15 years or so there have been a lot of PSK-31 software interfaces, so there's probably one that appeals to everyone.
I would imagine other modulation schemes would work in the ultrasound range, if you wanted to try SSTV or RTTY or perhaps a bidirectional error correcting protocol. AX.25 would be amusing and linux has kernel support and softmodem support if you can convince it to run at 20 KHz.
If you've got the bandwidth for Olivia and other modern modes I'd try those... I've made QSOs on HF where there is no discernible signal on the waterfall, works down to very low SNR. So you could get better range / lower error rate with a wider band / slower / more modern modulation method.
I would imagine doppler shift and multipath interference would be an interesting problem.
Re: Quietnet: Chat client that works over near-ultrasonic sound
#5Interesting... 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.
"surprisingly tinny laptop speakers have a good high-frequency resolution, and are able to deliver a pulse less than 10 cm long."
Re: Quietnet: Chat client that works over near-ultrasonic sound
#6I'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?
Re: Quietnet: Chat client that works over near-ultrasonic sound
#7I'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?
> hang on, like a piano
Starbucks is about to get a lot noisier. :)
Re: Quietnet: Chat client that works over near-ultrasonic sound
#8I'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?
Heh, I just visualized my laptop keyboard transposed onto an 88 key piano, and then tried to imagine what a typical vim session would sound like on it...
Re: Quietnet: Chat client that works over near-ultrasonic sound
#9Interesting... 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.
No one said that it wasn't possible to use high-frequency sound as a communication vector.
It was the sheer seamlessly interconnected complexity of the entire badBIOS affair that led to skepticism.
Re: Quietnet: Chat client that works over near-ultrasonic sound
#10I'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.
