How to protect from the USB Kill Stick

[anfang]

The USB Kill Stick aka USB Killer is a board with a USB connector and some capacitors. «When the device is charged, -200VDC is discharged over the data lines of the host device. This charge/discharge cycle is repeated many times per second, until the USB Killer is removed.» The manufacturers say that 95% of the consumer devices they tested are permanently killed by their stick.

How do you protect a USB port so that the device you are designing is immune from this kind of power surge problems?

[Rerouter]

fit large TVS diodes across your 5V and data lines, and live with 12mb/s usb,

[Jeff_Birt]

There are protection devices for USB data lines. I don't have a part number at hand but give it a search.

[mikeselectricstuff]

Screw defence - let's go on the offence - if a -ve voltage is detected, put mains on the 5V line..

[madires]

You should also buy the USB Killer Tester to get the 50% discount  Regarding the TVS, a diode bridge can be used to hide the large capacitance of the TVS. That method is used for Gigabit Ethernet over voltage protection, for example.

[TheBay]

One bad thing about it, it seems they have just used a Toshiba USB Flash drive case,
so would be pretty easy for someone to put it in a Toshiba branded case and fool someone. 

[Muxr]

Make a test device.. which acts as a USB host and exposes the data lines so that the original owner of the stick can place his hands on it. For the person who gave you the stick. It's cool because he/she has nothing to worry about if the stick is legit.   

[Fungus]

You don't deserve USB ports if you're accepting USB sticks off random strangers in the street.

Seriously.

[ZeTeX]

But why?

So yeah, you destroyed this whatever device that has a USB port, what now? what's the point? do you get money from that? why would anybody need it at all?
Usually people steal for money, kill for revenge\money\whatever.
but destroying a device for no reason? 

[radar_macgyver]

But why?

So yeah, you destroyed this whatever device that has a USB port, what now? what's the point? do you get money from that? why would anybody need it at all?
Usually people steal for money, kill for revenge\money\whatever.
but destroying a device for no reason? 

[anfang]

9 replies, 6 non-costructive messages. 0.33 S/N ratio. Not too bad.

Let's try to learn something today. What would the bridge diode + TVS diode configuration look like? How does it work? I haven't found anything about using the two together.

[FlyingHacker]

Would an SCR crowbar circuit be too slow?

Or could some optoisolator be used on the inputs? Would have do be made bi-directional.

[Zero999]

Add a boost converter to charge another capacitor to a few kV from the USB killer's 200V pulses, then send them back to the USB killer and kill the USB killer.

[daqq]

So yeah, you destroyed this whatever device that has a USB port, what now? what's the point? do you get money from that? why would anybody need it at all?
Usually people steal for money, kill for revenge\money\whatever.
but destroying a device for no reason?

Aside from some people just wanting to see the world burn, you can get all sorts of reasons for sabotage - political, economical, revenge... take your pick. Dropping a few in a parking lot in front of, say, a small corporate HQ you have a grudge against can have a crippling effect on them.

As to the original question, well, make the protections intelligent while beefing them up slightly (to maintain the bandwidth reqs as well as to enable them to survive the initial shocks) and in the case of a repeated overvoltage incident assume serious malfunction/hostility and shut off power? Maybe transformer coupling the USB signal through a saturable transformer, which would effectively limit the power transfered?

This is a good idea for a kickstarter product: USBCondom - extra layer of physical protection for your USB port/device (works both ways), complete with a ton of protection for all kinds of hostility.

Edit: On the site:

TEMPORARILY OUT OF STOCK! New stock available soon: 23/09/2016.

Well that's not disturbing at all...

[janoc]

Actually a TVS diode may not help. Those are often on the inputs already and they aren't made for repeated high current pulses. They are designed for high voltage, low current ESD events, not 200V and significant current, repeatedly. The diode will blow at some point and the next pulse destroys the device it was protecting. Game over.

Optoisolating the ports would certainly do the job - but also make the ports uber expensive (try to optoisolate USB 3!) and useless for powering anything.

Basically, the best protections against this sort of attack is to use common sense and not connect random crap to your computer. The same attack can be theoretically done e.g. using the power jack or through an SD card interface as well, then what?

[janoc]

This is a good idea for a kickstarter product: USBCondom - extra layer of physical protection for your USB port/device (works both ways), complete with a ton of protection for all kinds of hostility.

They are actually selling a "shield" for exactly this purpose.

Aside from some people just wanting to see the world burn, you can get all sorts of reasons for sabotage - political, economical, revenge... take your pick. Dropping a few in a parking lot in front of, say, a small corporate HQ you have a grudge against can have a crippling effect on them.

Well, a much better and a lot cheaper thing in such case would be to plant a normal USB stick with some malware than to simply destroy a computer of some secretary or office dweller. That would give the game up right away and do only limited damage, whereas a virus could literally wipe the company out of existence if they have sufficiently incompetent IT staff/practices.

This is simply dumb vandalism, nothing more.

[bktemp]

There is virtually no protection possible, because any protection with enough current handling capabilities will have too much capacitance for anything faster than a USB1.1.
The best solution is probably adding a self powered USB hub with some large protection diodes added on the 5V and 3.3V rails. It will get killed, but it will be much cheaper to replace than killing the motherboard.

[daqq]

Optoisolating the ports would certainly do the job - but also make the ports uber expensive (try to optoisolate USB 3!) and useless for powering anything.

I was actually thinking about this - USB 3.0 is AC coupled by default (as far as I know). Shouldn't just adding one of those little wide band RF transformers do the trick? They would go into saturation as soon as they'd get too much power and just not transfer it. They are cheap enough.

This is simply dumb vandalism, nothing more.

True. Please not that I am not defending it. It's an asshole thing to do and should be dealt with as such. I was just trying to explain why someone would do such a thing. That said, not everyone is capable enough to do a more sophisticated attack.

[Kleinstein]

A USB port open to people with bad intentions are a bad idea anyway. A damaged PC might be the smaller problem than. So best would be not using USB.

It could be more tricky if such a device is found or send by mail or similar. Still you can be lucky it is not a bomb, going off in your hand when inserted.

Anyway one should be careful with a USB stick from a dubious source - so a separate test device, less expensive, slower and better protected may be an option. Something like a really old PC might be an option.

[Rerouter]

why doesnt someone make a dumb adaptor with a diode and some leds that light up when the data lines or 5V rail go under 0V or over say 7V, and have it connect to a phone charger, that would be an ideal fast test bed for these voltage converter usb's

[rob77]

How do you protect a USB port

a direct hit with a shovel to the face of the person sticking that usb killer to your computer would do the trick (such a person would definitely deserve it)

[madires]

Let's try to learn something today. What would the bridge diode + TVS diode configuration look like? How does it work? I haven't found anything about using the two together.

Please see http://www.vishay.com/docs/88843/anusingr.pdf for example.

[Psi]

Screw defence - let's go on the offence - if a -ve voltage is detected, put mains on the 5V line..

Hahaha, i want to see this made so badly
A video showing various USB killers being plugged in only to explode themselves.

Coworker: Why is Ryan away sick today?
You: He tried to plug a USB kill stick into my PC
Coworker: What a dick but that doesn't answer my question
You: My PC retaliated and he now has 1st degree burns to most of his hand.

 

[2N3055]

 

I have few thoughts about this :

1. I doubt anybody doing this to my computer would have enough time to start laughing 
After that they would buy me a new computer..
So I don't think this could be called a joke.

2. Serious and deliberate sabotage and vandalism.... In that case that would be done on unsupervised equipment...  And if the protection is not on the motherboard and invisible why would they try it...
And they can and will use a hammer or a brick and smash it,  or plug USB directly to 220V AC, or just take the laptop and slam it on the floor 

No protection from that..

I know you wanted this as an engineering challenge, but that is what engineers do : find realistic and economic solutions to the problems..

I this case I recommend baseball bat as a protection device...

P.S. I don't condone violence, just joking... BUT... they would buy me new computer....

[2N3055]

Please see http://www.vishay.com/docs/88843/anusingr.pdf for example.

Well that is how is done for normal ESD...  but here energy can be much higher, and we don't know what and how the voltage is applied (differential between data lines, to the ground, reverse... )

So I think it is interesting as a challenge but in order to propose a solution, we would need to know what it really does, voltages, currents etc....
Youtube  is not a proof it even works... So unless somebody has one to reverse engineer it, in my opinion this topic is dead as to possible solutions..