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Comment by EMM_386 | Hacker News Reader

Yes, I was in the hospital waiting room recently and they had a charging station with each type of available cable.

I charged me phone, fully aware of these sorts of issues. I just went with my gut instinct that, in that environment, it's highly unlikely that the cables have been "trojanized".

The FBI can warn about it, but what can you really do? You just have to trust your judgement as to what you feel are safe charging stations, and which may not be.

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> but what can you really do?

Get a USB condom, for instance, practice safer charging. :)

This is a joke, but it could actually be a thing. An isolator that you can use to protect your device while using those unknown ports. I would call it an isolator though, or firewall, not what you called it.

It's not a joke, it's the (informal) industry term. See this for example:

https://www.zdnet.com/article/protect-your-data-with-a-usb-c...

https://lifehacker.com/use-a-usb-condom-to-protect-your-devi...

Cool, didn't know they exist.

Also now USB-C condom is also available, It was an issue since USB-C used data lines to negotiate voltage and I was tracking its need on my problem validation for a while now[1].

[1] https://needgap.com/problems/73-usb-type-c-condom-usb-cybers...

> Also now USB-C condom is also available

Oh, I didn't know that! So what is the solution for USB-C? How do the new USB condoms work?

I'm not completely sure, I read on reddit that USB-C condom has some form of proxy circuit to negotiate voltage; I hope someone with better knowledge in this can explain it better.

They make those. They are called data blocker cables and only have power pins, no data.

...which are really annoying when you do need to transfer data to your phone, but all you have in your bag are data-blockers ;)

Not a joke. The thing exists

You can even make a type of them yourself with rudimentary equipment, by cutting the data lines and connecting/not cutting the power lines. I believe you will lose the ability to negotiate faster charging, and I don't know if USB-C will work at all, but it still works otherwise.

Android asks me if I want to have a device to allow access, This probably prevents attacks against the upper layer protocols. Is the risk vector here the USB stack itself?

I think its possible to disable the USB 'protocol' in Linux, but it would require advanced permissions on android, which probably doesn't work out of the box, with IOS who knows or cares.

> Is the risk vector here the USB stack itself?

Yes, exactly. There are some comments here in the thread that discuss this in detail.

Get a tiny GaN USB-C charger, throw it in your bag, and forget about the public "charging ports"?

I bought like 5 of these, threw them in my bags and luggage, and I don't worry about charging like ever. And my devices charge fast.

If I'm doing long flights, I generally bring a single power brick.

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