81–90 of 91 posts
"Zooland is a new country where there are no regulations on electromagnetic transmissions.
Those regulations are from the past and stifle innovation and development in RF technologies.
They also encourage expensive communications.
Current RF regulations are a pure spacial and economic waste."
Earlier quoted context omitted.
From the article, the effective range seems to be around 10 feet. IIRC you are generally permitted to use whatever frequency you wish within a very limited radius as long as it is for "research purposes" Edit: this last point is wrong, as mentioned below exemptions seem to apply for certain frequencies with a low powered device https://www.fcc.gov/media/radio/low-power-radio-general-info...
Can you quote the FCC regulations that make this transmitter legal? (I'm assuming American law, the law in other countries obviously vary)
Earlier quoted context omitted.
Most keyboards don't have an antenna attached. While you can keylog a keyboard via emissions like this, you have to have physical access to the office to do so - at that point putting a usb keylogger inline with the keyboard is easier and more reliable. (or substitution your own keyboard with a real radio)
>Most keyboards don't have an antenna attached. What about meter long wire that runs from the keyboard to the back of the tower.
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But he doesn't have any amplification. Nothing is happening here that doesn't happen already with normal use of the UART. If what he is doing here is illegal then the RF pollution from using the UART normally would be too.
there is an antenna - just a wire - but that changes the equation a lot relative to what a normal UART does has part of a system that already meets FCC (or other) regulatory standards. I'm curious about the gain of the antenna and what consideration has been made re trasmit wavelength and the antenna wire length.
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For roughly the same price there are some DVR boards that could be converted to SDR operation once they're hacked. They already use embedded Linux although no source is provided. https://www.aliexpress.com/item/OUERTECH-5-in-1-AHD-CVI-TVI-...
You can also get HackRF clones, for about $100: https://www.aliexpress.com/item/HackRF-One-1MHz-to-6GHz-SDR-...
Anyway my point was that those cheapo DVR boards are just asking to be repurposed for other tasks, SDR is just one of them, that chipset specs are interesting. https://www.burglaryalarmsystem.com/pdf/Hi3520.pdf
Here are some firmware files for a few models, hopefully compatible with that one. Binwalk-ing them shows they're normal ARM Linux images.
https://domar.com/support/softwares-firmwares/ip-firmware-up...
Earlier quoted context omitted.
But he doesn't have any amplification. Nothing is happening here that doesn't happen already with normal use of the UART. If what he is doing here is illegal then the RF pollution from using the UART normally would be too.
there is an antenna - just a wire - but that changes the equation a lot relative to what a normal UART does has part of a system that already meets FCC (or other) regulatory standards. I'm curious about the gain of the antenna and what consideration has been made re trasmit wavelength and the antenna wire length.
Earlier quoted context omitted.
there is an antenna - just a wire - but that changes the equation a lot relative to what a normal UART does has part of a system that already meets FCC (or other) regulatory standards. I'm curious about the gain of the antenna and what consideration has been made re trasmit wavelength and the antenna wire length.
I think other commenters have already sufficiently explained this, but just to make it clear: Any wire functions as an antenne, also in a normal circuit where it is connected to something. The length of the wire will cause more radiation from some frequencies, but some designs will have wire length that matches some of the frequencies emitted by the regular communications performed (probably most of them actually - y…
That addition is what makes your original point wrong : "Nothing is happening here that doesn't happen already with normal use of the UART"
Earlier quoted context omitted.
there is an antenna - just a wire - but that changes the equation a lot relative to what a normal UART does has part of a system that already meets FCC (or other) regulatory standards. I'm curious about the gain of the antenna and what consideration has been made re trasmit wavelength and the antenna wire length.
I doubt the gain of a jumper wire is enough to cause any "damage".
So, reality is, this is likely very low-power and likely low-impact experiment and likely not cause a lot of issues with nearby devices that are designed to accept all interference and continue to function or fail gracefully.
But IMHO, it is a good idea for anyone doing these kinds of experiments to think a little bit about RF design and the impacts devices might have ..hence my other comment about the value of HAM technicians license & training (which is fun and pretty easy).
Earlier quoted context omitted.
Can you quote the FCC regulations that make this transmitter legal? (I'm assuming American law, the law in other countries obviously vary)
I don't live in the United States, and I don't give a damn about the FCC.
Additionally - if you are in Europe - regulations are defined by a body called ETSI (https://www.etsi.org/). For RFID these regs were quite different from FCC - we had to do listen before talk and a variety of other things to ensure compliance.
Well now we know what radio waves are produced by 0x55. How about other characters? I'm willing to bet that everyone's wired keyboard is an SDR so to speak and a well placed receiver can keylog you.
I wonder how fast you could toggle the capslock LED... hmm
Had to test ! :)