Hacker News Reader

Hacker News

Comment by fein | Hacker News Reader

Full thread

fein

Transmitting over HF waves via mic and speaker? That is currently blowing my mind.

Looks like my laptop needs a tinfoil hat more so than myself!

View on HN

Meet dog, your new security alert!

"ARF ARF" -"What is it, doggy? Someone's trying to hack the IRS dbase? Good dog!"

Chirp.io uses sound to transmit & receive links between nearby Android/iOS devices. IMO, interesting tech[1], thats more useful & less secure than bluetooth, for such use cases.

[1] http://chirp.io/tech/

Chirp is doing some really interesting work in this space, trying to improve the user experience of fast-forming short range communication.

My understanding is that Chirp uses audio to basically detect WHO you are standing near, but the actual data transfer happens over more typical links.

"An inherent limitation of the audio protocol is its highly limited transmission rate.

To send larger amounts of data, we have built a RESTful network infrastructure which allows arbitrary pieces of data to be associated with Chirp shortcodes. A sending device can thus upload a photo to the cloud, and obtain a shortcode representing it to be send over the air. A receiving device hears the shortcode over its microphone, and resolves it with a GET request."

> That is currently blowing my mind.

Not so much mine.

http://en.wikipedia.org/wiki/Acoustic_coupler

You could really hear the noise with these however. And there's the fact that the speaker was directly touching the microphone. It's cool that this works basically inaudibly across a room.

You could hear them because they were constrained to the voiceband. Frequencies outside 300-3400Hz were deliberately filtered out by the telephone system to maximize the number of calls that could be carried on a limited amount of copper.

"Across the room" isn't really interesting, either. I've decoded PSK31 across a room. Higher, near-inaudible frequencies would probably make the decode even cleaner.

Very unlikely. Laptops have crappy mics, they don't really have a response near 20 kHZ, as do crappy speakers. Also, this virus would have to analyze and deal with ambient noise. That's a pretty big level of sophistication for malware that can fit in flash memory.

So far, extraordinary claims, little data to back it.

Reply on news.ycombinator.com