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USB killer v2.0
From: Blibbet <[email protected]>
>Joe Fitzpatrick of SecuringHardware.com made a USB Sanitizer:
>https://github.com/securelyfitz/USBSanitizer/
>https://twitter.com/securelyfitz/status/583858610683441152
>https://www.youtube.com/watch?v=V60TksZd7uk
>Xipiter also sells the USB Condom.
>https://www.crowdsupply.com/xipiter/usbcondom
>I wonder if either would stop USB Killer 2.0?
I don't know about the specific products you mentioned, but it would be trivial to build an intermediate product to protect the products from each other. Â USB consists of four connections: Â GND, V+, and two datas. Â Aside from adding some intermediate series resistors of relatively low value, perhaps a few tens of ohms., diodes (silicon rectifier and perhaps Zener) would easily shunt over-voltages and block them. Â Obviously, there would be a limit to what a given protection system would protect against: Â Apply a 1000-volt, 10-amp power supply between V+ and ground, and SOMETHING is going to die! Â But the 'threat model' is far simpler for real-world dangers.
The tricky part is that you are supposed to be able to USE the power provided through the V+ pin for external devices. Â That's a convenience, but it is also somewhat of a danger. Â Who knows how much protection is already built-in to a typical computer's USB ports? Â A good 1000-volt PIV silicon diode in series with V+ would prevent an external circuit from forcing positive current into that pin. Â Similarly, another 1-amp diode, connected to the V+ and GND, backwards, would prevent V+ from being pulled appreciably below ground. Â Placing a 20 ohm resistor outboard of these diodes would limit current flow, etc. Â The trick is that you might want to use the entire capability of voltage and current from that USB port, without IR (voltage loss over a resistor or diode) loss. Â
There are also devices called "opto-isolators" (also called "opto-couplers") which could be used to provide well over 1000 volt isolation to the data signals themselves. Â Â Â Â Â Â Â Â Â Jim Bell, N7IJS
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