USB data blocker

GodAtum · April 30, 2023

Is this a new thing? I've been using charging ports on trains for years and never had an issue. Secondly, does this protect from overvoltage attacks?

TetraSky · April 30, 2023

It wouldn't protect against overvoltage. It's basically just a usb passthrough device without the data pins.

It might be possible to protect against overvoltage with some electronic internals, but considering these overvoltage attacks are in the hundreds, if not thousands of volts, very likely whatever you use on it will be fried regardless.

Maybe some tvs diodes in a circuit... But I doubt these cheapo passthrough devices have anything like that.

Here's a paper that provides a solution with tvs diodes for this type of attack, seems like a relatively simple circuit to make.

https://www.bourns.com/docs/technical-documents/technical-library/circuit-protection/publications/how-to-protect-mobile-devices-from-usb-kill-threats-white-paper.pdf

I don't know if it could actually work as I have not tried it. Maybe someone at LMG could try it? Could be a video idea.

A regular fuse by itself wouldn't work as they protect against high current, not high voltage.

Seabottom · April 30, 2023

51 minutes ago, GodAtum said:

Is this a new thing? I've been using charging ports on trains for years and never had an issue. Secondly, does this protect from overvoltage attacks?

This is in my opinion, a valid concern as there have been issues with ATM's stealing card info by using an attachable cover. Though in the case of USB ports, it's not straight forward to replace a receptacle so it seems to only be an issue for people with tin foil hats aka Americans.