3 ms·
Just for my own amusement, I tried to come up with one he hasn't done. He's done HDD LEDs, screen brightness, switch LEDs, and keyboard LEDs (those are 4 indepe
by marcan_42 6y ago
Just for my own amusement, I tried to come up with one he hasn't done. He's done HDD LEDs, screen brightness, switch LEDs, and keyboard LEDs (those are 4 independent papers). But he hasn't done camera LEDs!
So:
xxd -c 1 -p secret.txt | while read a; do for b in ${a:0:1} ${a:1:1}; do ffmpeg -y -f v4l2 -i /dev/video0 -t $((0x$b)) -f rawvideo /dev/null ; done; done
That leaks a file via the camera LED, PWMing it at 4 bits per pulse (16 different pulse widths), tested on my iMac. Can I get a paper now? :-)
- isoprophlex 6y ago"Anonymous Reviewer 2" stipulates that you include twenty citations to papers written by a single lab before your paper can be accepted for publication :^)
- rrobukef 6y agoAnd at least one or two to his papers... Of course, he's anonymous!
- geckyrc 6y agoThis website is pretty cool sometimes.
- deleted 6y ago[deleted]
- im3w1l 6y agoYes maybe it's too many papers for too little material. But I do think even your the code you posted has some merit (even if not enough to stand alone).
- anfractuosity 6y agoHeh, I think the keyboard LED trick was mentioned in Cryptonomicon iirc. I created one that takes a mere 14 minutes to transmit 'hello' using a cd drive's movement: https://www.anfractuosity.com/projects/cditter/ https://www.anfractuosity.com/projects/cditter/
- studius 6y agoThe camera led is cool. That might work in a noisy environment, but it draws attention visually, which might not be great. Also, (1) users tend to cover their cameras with tape or post-its, (2) why would a super secure endpoint have a camera if it wouldn't be on the network, (3) slight chance of being noticed on external/detached security webcam.
- Phait 6y agoI went through the command trying to understand what you did and I realized I know nothing about using the CLI properly. So cool!
- throw0101a 6y ago> That leaks a file via the camera LED, PWMing it at 4 bits per pulse (16 different pulse widths), tested on my iMac. Can I get a paper now? :-) Using (security) camera LEDs was already done: * https://arxiv.org/abs/1709.05742 https://arxiv.org/abs/1709.05742 :)
- xyproto 6y agoThat's nifty! Here's an alternative way to pass the bytes to ffmpeg, using hexdump (does not require vim) and `read -n1` (works in bash, but not in zsh): hexdump -v -e '1/1 "%02x"' secret.txt | while read -n1 b; do ffmpeg -y -f v4l2 -i /dev/video0 -t $((0x$b)) -f rawvideo /dev/null; done
- r00fus 6y agoKeyboard LEDs using morse code has been done before in literature (Cryptonomicon). This is a nice modernization of the same approach.