From: Razer <Rayzer@riseup.net> On 10/15/2015 03:22 AM, Georgi Guninski wrote:

...

 http://www.theregister.co.uk/2015/10/14/sneaky_220v_usb_fries_laptops/ An internet mischief maker has built a USB stick that delivers dangerous 220-volt shocks to PCs, destroying them in the process. Tentatively speaking, No. I don't think so... The circuitry is designed for 5 volts, and the capacitance available throughout the device is so low almost no current would be available either. Sorry, but you are wrong there.  The amount of power available through a typical USB connection is probably many hundreds of milliamps, at 5 volts.  And this power could be converted, by a switching power supply, to hundreds or even thousands of volts, and stored in an internal capacitor.  Once switched on, internally, and applied back to the data signals, the device could easily fry a few levels of circuitry in the computer.  It would be essentially unrepairable.

           Jim Bell, N7IJS.   The World's Last Tech-Plus Ham

From: Blibbet <blibbet@gmail.com>

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.  USB consists of four connections:  GND, V+, and two datas.  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.  Obviously, there would be a limit to what a given protection system would protect against:  Apply a 1000-volt, 10-amp power supply between V+ and ground, and SOMETHING is going to die!  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.  That's a convenience, but it is also somewhat of a danger.  Who knows how much protection is already built-in to a typical computer's USB ports?  A good 1000-volt PIV silicon diode in series with V+ would prevent an external circuit from forcing positive current into that pin.  Similarly, another 1-amp diode, connected to the V+ and GND, backwards, would prevent V+ from being pulled appreciably below ground.  Placing a 20 ohm resistor outboard of these diodes would limit current flow, etc.  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.   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.                 Jim Bell, N7IJS

Well, the reason I am the "last tech-plus ham in the world" is simply that as a byproduct of pissing off the Federal government, it refused to handle my timely-filed (January 2010) license renewal.  However, the law apparently says that I am a legal ham as long as the FCC is processing my renewal, which seems to amount to "forever".  So, while everyone else was upgrading (or expiring) I remain "the last tech-plus ham in the world".    https://www.reddit.com/r/amateurradio/comments/3dt9d5/why_does_ae7q_show_nov... My understanding, also, is that I am actually still entitled to merely sign a form to become a general.  Although, there is no guarantee that the FCC would act on THAT, either.          Jim Bell, N7IJS  From: Razer <Rayzer@riseup.net> To: jim bell <jdb10987@yahoo.com>; cpunks <cypherpunks@cpunks.org> Sent: Thursday, October 15, 2015 1:41 PM Subject: Re: USB killer v2.0 Are you really? Sigh... Shoulda never let my callsign lapse in the early 2000s, I'd be an advanced by now, and we'd be vying for who dropped dead first. RR, KC6NFR-expired On 10/15/2015 12:34 PM, jim bell wrote:

Jim Bell, N7IJS.  The World's Last Tech-Plus Ham

On 10/15/15, jim bell <jdb10987@yahoo.com> wrote:

... However, for REAL damage, it would be useful to pulse the kilovolts into the magnetron: Generally if you increase the voltage by 10, the power increases by 100. Feed that microwave magnetron with brief (microseconds) pulses of 40,000 volts, rather than 4000, and it will probably generate close to 100 kilowatts. It would be necessary to establish that such a system will not arc with over-voltage, either within the waveguide or the associated high-voltage wiring.

high voltage solid state built into shielding around the waveguide/magnetron cavity presents smallest external hazard and compact too. of course, another order-of-mag level up in explosively pumped EW weapons :) now for buckysheet airogel supercapacitors to get cheap... best regards,