USB Condom: charge your devices without allowing sneaky data-transfers


#1

Originally published at: http://boingboing.net/2014/08/25/usb-condom-charge-your-device.html


#2

I have a beef with the mentioned item: How do I pocket it without damaging it? It’s a raw PCB!

Fortunately, there’s competition, producing something more pocket friendly in Apple and non-Apple versions:


#3

What are the extraneous components ((R1, 2, 3) for? The product description says it’s just a USB passthrough with the data lines clipped - so why are those resistors there?


#4

Newer Apple devices require a voltage level on the data pins or the device wont charge. I just modified an old iPod docking station to accommodate my iPhone 4 for that reason.


#5

I have these, they seem to work very well, and do speed up charging of a computer and the like (computers may be too smart for your own good, and cut your phone down to the 2.5w spec of usb 2.0, when it could handle 10+w).


#6

Voltage divider for Apple stuff – they expect a certain voltage on the data pins. Makes DIY chargers a pain.

Edit: didn’t notice that @vector had responded to ya… I need to quit posting from my phone.


#7

You aren’t likely to damage it by carrying it around with your pocket change, but you’d probably tear a hole in your pocket lining. Corners of PCBs are hell on fabric.


#8

Why is this a circuit board?

Wouldn’t a little flat piece of plastic, custom-cut to block the data pins, be far more elegant, affordable, and a better fit for the condom comparison?

ETA: ohhh, Apple crap. I’m little inclined to design accessories around the whims of devices that refuse to play nicely with others.


#9

Xipiter, the security consultancy who created it, has already done one production run and shaken out the bugs, so it seems likely that they’ll be able to fulfill orders again – but as with all crowdfunded projects, caveat emptor.

It looks simple enough. I would probably play it safe and put in $5k as a starting point, even if you know what you’re doing for a small batch electronics production run.


#10

As far as I’ve followed the issue it’s actually Apple that plays nicely by following the USB spec by not simply drawing beyond 100 mA without negotiation.


#11

The final product has a clear shrink wrap over the printed circuit board for protection and to prevent snags.


#12

There is no negotiation for a device that only charges stuff…
From what I recall when making a DIY voltage supply/charging station, the charging standard just requires shorting the data pins with a resistor – Apple has a completely different scheme for supplying a certain voltage to each data pin (the voltage on the data pins tells the iPhone/etc what sort of current the charger can supply).


#13

Yes, but that is a relatively recent addition to the standard as a reaction to non-compliant dumb devices.


#14

Not that much malware is targeting these devices, but it’s baked into the new builds of WP8.1 I guess:

It’s not hardware though.

[Insert Obligatory Anti-Microsoft Verbiage Below Here]


#15

A new cased version of the USB Condom is coming out soon. An official announcement in a few days …

https://twitter.com/USBCondom


#16

At least you’re keeping it charged. :smiley:


#17

So how is this different from the $8.99 “fast charging” no-data cable in Cory’s link, or the $6.99 tiny “fast charging” no-data dongle in @kpkpkp’s post?

Why Kickstart something that already exists, for more money? Do people think it’s different because it’s marketed as a “condom?”


#18

A few other bits and pieces (I know that I have this problem with an older Motorola dumbphone, and that it isn’t terribly rare; but I don’t know of a comprehensive list of device behaviors) expect various fiddly oddness on the data lines when connected to a charger.

Sometimes it’s pure lock-in, or an attempt, some times I think it tells the device something about the current capabilities of the charger. Inelegant; but cheaper than throwing a whole USB host into a wall wart I suppose.


#19

This reminds me of a post I made quite some time ago:

plus ça change!


#20

Well, if you’re extra-vigilant about protection, you can both visually inspect the entire circuit, and test the broken-out pins to confirm nothing dodgy is happening. Not possible with devices encased in (likely Chinese, with its implications) plastic.