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USB "Condom" Allows You To Practice Safe Charging
MojoKid writes "Yep, a USB condom. That term is mostly a dose of marketing brilliance, which is to say that grabs your attention while also serving as an apt description of the product. A little company called int3.cc has developed a product—a USB condom—that blocks the data pins in your USB device while leaving the power pins free. Thus, any time you need to plug a device such as a smartphones into a USB port to charge it—let's say at a public charging kiosk or a coworker's computer--you don't have to worry about compromising any data or contracting some nasty malware. It's one of those simple solutions that seems so obvious once someone came up with it."
My MP3 player, the nearly 10 years old Cowon D2, actually came with a power-only USB cable. Maybe their goal was to save money on copper.
This wouldn't allow devices to detect fast charge capability, as that depends on resistances between data pins and power pins, or high-level protocol negotiation if it's an intelligent host with this capability. Devices will only charge slowly (100mA) if at all.
You could do that. I could also not buy your broken charger.
I run: Windows, OS X, Linux, FreeBSD. Just because you have a hammer, doesn't mean everything is a nail.
If someone has physical access to your phone unsupervised, ALL BETS ARE OFF.
I run: Windows, OS X, Linux, FreeBSD. Just because you have a hammer, doesn't mean everything is a nail.
I've made my own, but you can buy them inexpensively. They're really convenient if you're, say, trying to keep devices from popping the VMWare Fusion Mac/Linux selection dialog or complaining about ejection.
So, yeah, this guy made a board, but a cut-line extension cable has been the answer to this problem for a while. Some devices may fuss or trickle charge, but it generally works.
This over-engineered nonsense in the article is ridiculous.
Why does this require a big PCB with three ICs? Why not just simply remove pins 2 & 3?
I've apparently made 'USB condoms' myself. A male and female usb connector soldered end-to-end, the data pins shorted together.
This enables my ancient HTC Desire to recognize any usb charger as a dedicated charger, and charge with up to 1 A (in reality significantly less). It is a low tech solution that works.
So why so much electronics on the board??
In the standard A and B plugs the data pins are recessed compared to the power pins. Grab any standard cable and you can slide it in until the power makes contact, giving you charging without any data connection.
I've been doing this for years to charge a MP3 device without it being mounted by the host computer.
You could do that. I could also not buy your broken charger.
But you know what you're doing. Social engineering will always work on some people though:
"My phone is flat and I really need to take a photo of my big mac to show my friends, can I borrow your charger?"
"Sure, here you go"
"It's not working"
"Try taking that adapter thing off, it's probably mucking up the charging"
Faced with the horror of eating their big mac without it first being photographed, I think you can guess how this story ends...
There's a current KickStarter project called LockedUSB which does something similar, but which also includes a power management chip in order to negotiate higher power charging levels that normally require data connectivity. LockedUSB doesn't appear as big or ugly as the one in TFA. (Full disclosure: I'm a backer)
A little company called int3.cc has developed a product—a USB condom—that blocks the data pins in your USB device while leaving the power pins free.
If you consider something that blocks the middle of the male end but leaves the sides open to be a "condom," you might want to see a doctor. Soon.
If you consider that it allows for insertion without allowing the flow of information, the comparison might be more correct than you think.
A little company called int3.cc has developed a product—a USB condom—that blocks the data pins in your USB device while leaving the power pins free.
If you consider something that blocks the middle of the male end but leaves the sides open to be a "condom," you might want to see a doctor. Soon.
If you consider that it allows for insertion without allowing the flow of information, the comparison might be more correct than you think.
Yes. But I hate charging with these 'cause it just doesn't feel as good...
When I first got a Playstation Vita (What? Why is everyone laughing?), I had a USB battery to charge it on the go - but it wouldn't work! Of course, Sony said that it would only charge from their own Vita power bricks, but that was obviously just PR - it was just a USB A connector on the business end, after all. After some investigating, I found out that the Vita checks for shorted data pins, and if it doesn't find them, it won't charge (unless it's connected to a PS3 or computer.) Other products use different methods, such as sets of resistors to put a certain constant voltage on the data pins; said voltage varies according to how much current the adapter can safely provide. Apple is a big one for this method. The solution I went with involved getting some USB swivel adapters, cutting open the female sides, and soldering the data pins together. This tricked the Vita into thinking it was connected to its own power brick, so it drew the full 1.5A from any USB source. This could be dangerous, if you have it on a cheap charger that can't safely provide that much. Since then, I've used these devices for charging other things that use the same method of identifying fast chargers, and even for data safeguarding, as this article suggests. If you don't want to do the work yourself, such things can easily be purchased (they weren't as prevalent at the time). -- As several other people have said, I'm curious what all the intermediate stuff in this USB Condom is for. Perhaps it's to do with negotiating higher power draw from host devices, and making your device think it can pull however much it wants, for safe, fast charging? -- Sources: http://www.dannychoo.com/en/post/26419/PS+Vita+USB+Mod.html http://www.amazon.com/dp/B007Y3L5RI
On what screen? You don't have access to a screen. You could refuse to provide power if you don't see data pins, but you can't control how that gets displayed. And I suspect anyone who gets one of these will pretty much be suspicious of suddenly finding a charger which needs that.
Note that there's at least one sort-of-similar example: The iPhone won't charge from a USB hub if there's no computer. It'll charge from a plain charger, or from a computer, but not from a hub. In this case, it's that there's data pins but not quite enough data on them.
My blog: http://www.seebs.net/log/ --- My iPhone/iPad app: http://www.seebs.net/seebsfrac/
A capacitor connected between D+ and D- lines will block any USB negotiation and data transfer without interferring with the DC levels used to "negotiate" charger capacity.
Well... if you're going to remove a device specifically designed for device security because some unknown third party device/person tells you to - your security problems aren't of a technical nature. As they say, there's no technical fix for stupid. Not saying it won't happen, but there's not a lot a security accessory vendor can do to protect against that.
I run: Windows, OS X, Linux, FreeBSD. Just because you have a hammer, doesn't mean everything is a nail.
That's why I tamper-proof my phone with Windows 8, and a picture of Justin Bieber for the locked screen.
Well... if you're going to remove a device specifically designed for device security because some unknown third party device/person tells you to - your security problems aren't of a technical nature. As they say, there's no technical fix for stupid. Not saying it won't happen, but there's not a lot a security accessory vendor can do to protect against that.
So true. Outlook blocks links in messages it has moved to your junk mail folder. Consequently all spam now says "if links aren't working, please move this message to your inbox". Stupid will find a way.
All I have to do is feed some "connection error" kinda stuff on the screen until the guy takes off his condom.
For anyone new here this is a fine example of geek sexting...
My ism, it's full of beliefs.
I've been in airports, and had people w/ just a USB cable ask me if they could plug into my laptop to charge ...
Luckily, as I usually fly southwest, the two times it's happened I was able to point out that there was USB charging available from their power points.
(when people think I'm mean for not sharing power in other situations, I'll break out the 'It's not how many USB sticks you plug into your laptop' PSA reference) ... I'd love for USB sticks to bring back the hardware write-only switch.
Personally, I wouldn't need one of these 'til my current phone dies -- WebOS will assume charging only unless you specifically enter your passcode to allow it to function as a USB disk when you plug it in.
Build it, and they will come^Hplain.
The moment I plugged it into my laptop, even before plugging the iPhone in, the laptop turned off. No damage. Being naturally curious I tried it again and it was repeatable.
Sounds like you are a scientist. Congratulations!
Why do these solutions need to be soo complex?
Corner cases usually. The power requirements of devices plugged into USB are a bit unpredictable so it's more complex than many realize. I agree with you though. It seems like they are adding a bunch of needless complexity to make up for some poor initial design choices.
As an example of poor design choices, it has always mystified me why they made USB a keyed connection instead of a reversible one. I'm not overly impressed with Lightning cables from Apple but one of the things Apple did right was to make it so you didn't have to fuss with worrying about which way was "up". There is no reason USB could not have been designed so that you didn't have to worry about orientation when plugging it in. It's got 4 conductors (5 in some cases) so it wouldn't exactly be rocket surgery to put enough brains into the controllers to negotiate the connection. They could have also solved it with a better designed (albeit more $) connector. Hell if they were really lazy they could have even done it by adding more wires. But instead they chose the cheapest possible route and pretend that putting the USB logo on one side of the connector somehow makes obvious (it doesn't) which way to plug it in.
Their domain int3.cc is an allusion to the one-byte software interrupt instruction on 16-bit x86 systems. Opcode 0xCC disassembles to int 3, and it's most frequently used by debuggers, which patch a single byte of code with it to make a breakpoint.
Qu'on me donne six lignes écrites de la main du plus honnête homme, j'y trouverai de quoi le faire pendre.
would a charger need to current limit the power if the device tries to draw more than it can provide?
Because many chargers are connected to devices or power lines (110VAC etc) that can supply MUCH more power than the cable can handle. The wires inside a USB cable used for power are often 24 gauge which can only handle a relatively modest amount of power before they overheat. You need a charger that is smart enough to not exceed the limits of a USB cable even if the device is dumb enough to "request" that much power. Otherwise you could end up with a molten wire rather easily.