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Most electronic payment systems have very short lives.

• Exxon Speedpass (1997-2004 for uses other than gas stations) Tried, then dumped by McDonalds.
• RFID chip embedded in arm (2004)Used in some nightclubs in Barcelona.
• i-Button (1994) A ring or fob mounted contact-type ID device. Used for bus ticketing in Turkey, and for login security elsewhere.
• EMV Contact-type smart cards. (1995-date) Popular outside the US, especially for stored-value applications.
• American Express ExpressPay (2005). Tried, then dumped by McDonalds. Still used by OfficeMax.
• T-Cash (2011) Send money from your cell phone. Tried in India.

>.> Reading comprehension fail?

Honeywell's thermostat is parasitically powered, not their sensors. I'm saying the general technique - drawing power from other devices over e.g. data lines - is obvious to anyone skilled in the art of circuitry.

Here's a Maxim DS18S20 1-wire parasite-powered digital thermometer chip. http://www.maxim-ic.com/datasheet/index.mvp/id/2815

Arduino parasitic power. http://www.arduino.cc/playground/Learning/OneWire

Hell. RFID chips derives power parasitically from the transmitter.

Maxim (not the magazine) has nice but expensive buck and boost converters with decent documentation and reference implementations. I used the MAX-756 boost converter on a single solar-cell-powered XBee data node. It boosted 1.2V to 3.3V, no sweat.
Naturally they came out with the MAX1674/MAX1675/MAX1676 parts the day after I purchased the 756.

Wow, I must be having a huge problem making myself clear.

The idea is that you hack one of these: http://www.maxim-ic.com/datasheet/index.mvp/id/5232 [maxim-ic.com] in line on the USB data lines, and control it with a GPIO from the CPU. The data lines are only connected when the phone is unlocked. So it really doesn't matter what you device you connect to the phone's connector, it won't be talking to the phone.

Yes, you were not clear. I see no way to naturally infer you meant adding a surface-mount component and associated circuitry to operate it from your posts.

That's kind of going to extremes even for someone with decent electronics skills. You've got any number of space constraints even with a SM switch considering the variety of phone models/designs out there. In most cases you'd need to add a PCB for the switch & circuitry, as the component-density of most cell phone PCBs doesn't allow for sufficient space to add much of anything.

Doing surface-mount PCB component-level work at the average electronics hobbyist workbench isn't easy or practical either. I know, I've worked on electronics for over 35 years. It takes some specialized tools and skills to work with components like that switch which is only 2mm a side with multiple connections.

Besides, if one is doing things that would make it dangerous for the cops to grab data from one's phone, one is more than likely using a disposable phone anyways. A quick slice with an X-Acto knife is a much more reasonable, efficient, and practical precaution that doesn't take a lot in the way of time, trouble, tools, or skills. A good thing for something you may end up ditching in a fire or the bottom of a large body of water.

Sure, it'd be nice (and may even be possible in some cases) to have custom surface-mount goodies installed in your phone, kinda the way that having "Q" from the Bond films customize your ride would be nice, but not really practical or realistic in most cases.

Strat

Wow, I must be having a huge problem making myself clear.
The idea is that you hack one of these: http://www.maxim-ic.com/datasheet/index.mvp/id/5232 in line on the USB data lines, and control it with a GPIO from the CPU. The data lines are only connected when the phone is unlocked. So it really doesn't matter what you device you connect to the phone's connector, it won't be talking to the phone.

Most likely reason for this might be that, there might be a loose connection and the phone detected the connection as a data connection instead of pure power connection rather than anything sneaky happening. This is done b shorting out the D+, D- pins through a ~200Ohm resistor which indicates to the phone that it can draw more than 500mA from the source (500mA is the maximum current a standard USB port can provide on a computer). Reference: A good source: http://www.maxim-ic.com/app-notes/index.mvp/id/4803#3 Especially the last paragraph in the section header. http://en.wikipedia.org/wiki/MicroUSB#Power

What you want is an iButton. It can be used to store a crypto key, and the device itself can be secured both cryptographically and physically. I would assume that with enough effort you could get the die out of an iButton but the device is designed to prevent this, providing physical tamper security; Crypto iButtons have a crypto processor built in. Then there's Java iButtons, which include a little bitty processor and which run tiny little Java applets. They have already come and gone (ISTR you could actually buy them at one time, and not just get them at one JavaOne conference) but they seem handy. There is actually a monetary iButton but I didn't read any of the datasheets.

poop on having a button though, you just touch the button to the terminal.

I have emailed them and suggested they consider the following and I'm sure they've had tons of others asking for a network connection.

http://www.maxim-ic.com/datasheet/index.mvp/id/6790

"Housed in a 32-pin, 5mm x 5mm QFN package, the MicroPHY® is the smallest Fast Ethernet PHY available that provides a full 802.3 media independent interface (MII) to the system media controller."

Considering that I'm not planning on doing this myself, I just obsessed way too much on finding an answer for you. For starters, the Colorado time broadcast is a pretty good choice:

The time codes are sent from WWVB using one of the simplest systems possible, and at a very low data rate of one bit per second. The 60,000 Hz signal is always transmitted, but every second it is significantly reduced in power for a period of 0.2, 0.5, or 0.8 seconds: 0.2 seconds of reduced power means a binary zero, 0.5 seconds of reduced power is a binary one, 0.8 seconds of reduced power is a separator. The time code is sent in BCD (Binary Coded Decimal) and indicates minutes, hours, day of the year and year, along with information about daylight savings time and leap years. The time is transmitted using 53 bits and 7 separators, and therefore takes 60 seconds to transmit. A clock or watch can contain an extremely small and relatively simple antenna and receiver to decode the information in the signal and set the clock's time accurately. All that you have to do is set the time zone, and the atomic clock will display the correct time.

(from the Galleon corporate website)

As far as integrating that into this specific project, you may want to add a processor dedicated to just decoding the time signal - one bit per second, read over a full minute, is more attention than the primary processor probably wants to give to the radio. Once the time is read off of the radio, though, it's pretty simple to dump it into the clock. The clock chip's data sheet gives details on the serial protocol used to send data to the chip, and on pg. 8 it tells what registers to address for setting time and date.

I'd say it's possible, and would probably be easy for someone who knows what they're doing =)

If you do end up making an add-on circuit for this project, just make sure you publish it; Ladyada might even be willing to host it.

If you can solder: http://www.maxim-ic.com/products/1-wire/

Or if you can't: http://www.hobby-boards.com/catalog/index.php?cPath=24

Or if you sign up on Maxim's website they'll send you 1-2 samples of some of their products. Very awesome indeed.

1-Wire is awesome. I'm currently using it in my house. While it doesn't do everything, there are quite a few modules for different things.

Those are just the pre-built options. Maxim has quite a few chips that do different things. People have also used things in very creative ways. The wind direction gauge is just a position feedback sensor on a mechanical device to point towards the wind.

And no 1-wire home setup would be complete without OWFS (One Wire File System). Works quite a bit like /proc. You can query your temp sensors with 'cat' and turn on relays with 'echo'. Also has libs for php, perl and other languages so you can use scripts. Caching so you don't hammer the bus.

Since I installed my HVAC controller before the temp sensors (Open Loop!) I went with a super4 relay board. They have linux code, but uses the proprietary FTDI drivers, I used libftdi and write my own. I wired it up in parallel to my thermostat, which I set to 50F. When I was driving home I'd kick it on and when I got home I'd kick it off. If I was hot, I turned it off. Etc. Also kicked on (via cron) at 7 am. (I grew up in an old farm house, so 60F ambient is fine for my single life).

I also have it on the 'web' checking an e-mail address that I can text from my phone. "heat" kicks things on "off" kicks things off. Nothing fancy yet.

Am I supposed to be impressed? This seems like a non-story to me. Here it says that the MTBF of LEDs is between 100000 and 1000000 hours. That's 10 to 100 years, 24 hours a day. (or 50 to 500 years if used 5 1/2 hours a day, assuming burnout only in operation)

Then let them put a micro black box http://www.maxim-ic.com/products/ibutton/ to show it was running a non-authorized battery when it exploded.

I remember when I first realized that you could double your row-column population. Then I extrapolated it to its logical conclusion... that you could connect n(n-1) leds where n is the number of control lines. I was so proud! Then in an unrelated search I learned that not only was this an established technique, but it even had a cute name: Charlieplexing.

There's a neat little story here:

http://www.maxim-ic.com/appnotes.cfm/an_pk/1880

>shifting the source of power from an inefficient source to a more efficient one is an improvement. most cars average around 20% efficiency while even coal plants get around 35%.

Diesel cars have an energy efficiency of 45%
But that means that 45% of the energy stored in the petrol is converted to movement energy.

Cogas plants can have an efficiency of 60% (if you can make use of the heat: 85%).
This figure is the amount energy of coal converted to electric energy (via movement).
It still has to be distributed to the cars (7% power grid), used to charge the battery (4% charger) and converted back to movement (10%) results in 48% efficiency (68% heat).

I (knowingly) neglected the transport of the energy to both the car and the factory, and the use of regenerative braking in possible hybrid diesel and fully electrical cars as both would go far behind a back of the hand calculation.

But you can see, if you are going with just a 30% efficient coal plant, you better stick with a new diesel car, than an EV.

"I realize you're joking (and I agree that the parallel port is useless), but RS232 is still pretty useful."
You may want to re think that. Take a look here.

http://www.epanorama.net/circuits/parallel_output.html

And here
http://www.hardwaresecrets.com/article/233

And here
http://www.phanderson.com/stamp/intro/intro.html

And here
http://www.maxim-ic.com/appnotes.cfm/an_pk/3230

For your average PC user the parallel port is pretty useless. But for a hardware hacker they are great!

What's wrong with "contact" payment technology?
The iButton looks like it can do pretty much everything RFID can, without the risk of sniffing.

Yeah, I wondered about that too. If you look at the progress of modulation technology the trend is for signals to look like white noise. And spread spectrum allows a bunch of signals in the same band, all beneath each other's noise floor thanks to the magic of despreading. Plus in a cell based system you'd want to minimise the RF power radiated outside the cell because it's wasted.

You could cover the planet in spread spectrum communication cells and have no emissions into space. Even broadcast systems are probably hard to detect from space, let alone light years away.

100 microseconds every 10 miliseconds is only 100Hz. I'm not sure why car makers use such a low frequency, but I can see it as well and it is kind of distracting. I can also see colors in DLP projectors and TVs if I move my eyes quickly enough.

I'm using a homemade LED light as a desk lamp right now, and I can't see any flicker. The PWM chip controlling the voltage is running at around 300KHz, and I can dim it all the way to zero without any flickering. Even if it was running at a lower frequency, the filter capacitor is smoothing the voltage.

I used a 95 lumen Luxeon Rebel Star for the LED (but you can get up to 180 lumens with no additional power used) and a MAX774 for the PWM. The total cost was under $40, and it is at least as bright as a 15W halogen light. I took the circuit from a Maxim application note.

>so epoxy potting removal is incredibly easy to me.

Out of curiosity, how do you do it? I've used a combination of soaking in acetone and physically chipping/milling the stuff away, but I'd love to know better techniques.

>The ONLY way to make these toys secure is custom chipsets. power up chipset and then only decrypt the contents of the flash after the 12 digit key was entered on the little pin pad. But nobody is going to make that.

Read about the Maxim DS3600 family of chips some time. Keys stored encrypted on-chip, chip's a microSMD so you can't get to the pins, has massive on-chip detection facilities for eg. case tampering, power glitches, and temperature changes, all of which trigger it to wipe all its stored keys and optionally wipe other things to which it's attached, and uses weird repeated XOR writes of the encrypted keys so they don't build up oxide charges that'd allow you to read the memory once you've torn it apart.
That chip's going to be hard to fool.

In the early 1980's, the US produced intermittently buggy chips which we sold to the USSR in full knowledge that they'd disrupt production facilities. It worked very well. Why, then, wouldn't China do the same thing?

As someone who works in chip verification, I can tell you it's very difficult with most chips to do this, as long as the chips are designed in the US -- which is still largely the case, that they're designed here and produced in fabs in China (because labor's cheap and they don't care if their workers are exposed to HF and silane as long as money's coming in.)
You know *exactly* what size your chip die is. If the silicon comes back from the fab with a different-sized die, it will be very obvious. So nobody can put extra stuff onto an existing die. Die size is the single most critical aspect of most designs, because of the cost, so existing designs are jammed just as tightly as they can possibly be. You can't put more functionality into an existing die size. The problem, then, is letting your design out. (And even then, a competent chip designer could probably spot strange material on a smaller die because they're familiar with how the layout is supposed to look.)
There are some amazing military-grade chips out there. I was reading about the Maxim DS3600 the other day -- on-chip encryption and tamper-sensing, including detecting temperature changes and reacting by blanking all the on-board memory and stored encryption keys in nanoseconds, far faster than dumping liquid helium onto the chip would be able to freeze the memory for decoding. (They use some whack process for continually load-levelling and rewriting the keys so you can't use stored oxide charge to read what was there before it got blanked, either.) That kind of stuff is on the common market, available for anyone to buy. I assume the military has better stuff yet, and espionage people even better.
At the end of the day you have to be able to trust someone or you'll just crouch in your basement. But there are ways to verify a chip's functionality and look for clearly bogus interactions. Our chip test systems make it easy to distinguish chips from different silicon lots, much less from different fabs. As always, if you buy the cheap stuff you don't know what you're getting, but if you spend the money to do some research, you'll have a much, much better idea of what you're getting. In this case, money in the millions of dollars, granted, but if you're designing military-grade stuff, well, that's why you buy from companies with a track record of producing trustworthy stuff.

Well, NEC Electronics does, and they're even 90nm! (650nm and 350nm versions also available.) Also Freescale, and Texas Instruments, and Maxim (no, not the magazine) and ... lots of people, especially those who want to have decently-performing analog circuits.

You kids these days thinking everything is CMOS. Go ahead and try to make me a 10GHz RF circuit in CMOS.

Like you said, it's already put inside of every lithium battery made, that's not the problem

I admit I'm being a bit of a pedant here, but it sounds like what you want aren't lithium batteries, but lithium cells. I would guesstimate that the mass-produced cost of the safety circuitry is somewhere between $3 and $10, which would double or quadruple the cost of a cell. (a MAX1737 which only implements charge control, not discharge control, is $2.85 for lots of 1000, and requires supporting components. The LM3621 is less expensive at $1.40 but has the same limitations), and some room in each cell (reducing capacity and adding weight). You may find the R/C aircraft hobbyists' attempts to use lithium in their homemade battery packs interesting reading.

If my guesstimation is wrong, there's probably a profitable business waiting for you.

There's a technote on using the 5250 w/RSA http://www.maxim-ic.com/appnotes.cfm/appnote_numbe r/4004

http://www.maxim-ic.com/quick_view2.cfm/qv_pk/3932

There's a technote on using the 5250 w/RSA http://www.maxim-ic.com/appnotes.cfm/appnote_numbe r/4004

http://www.maxim-ic.com/quick_view2.cfm/qv_pk/3932

If you can't find it in a DIL (or DIP) then digkeyhttp://www.digikey.com/scripts/DkSearch/dksu s.dll?Criteria?Ref=33490&Site=US&Cat=34079261 sells adapters. Many manufactures will also send you a few samples of chips for development work, they generally send you ~5 of any sub $15 chip for free (including shipping). Maximhttp://www.maxim-ic.com/ is one of the best for sending out free samples quickly, but analog deviceshttp://www.analog.com/, and just about any of the others send out freebees as well.

If you are going to be away a simple list to start with is:
1. Conserve electricity, unplug everything or just flip your breakers off (if you have nothing remote to access)
2. If you use natural gas, you can shut it off at your house or just cut off the heater/water heater.
3. Turn off your water. Look for your water shutoff valve and just turn it off...
4. Cover your pipes! If it gets cold, even if you've shut off your water, wrap your pipes up near the shut off valve.

If you need something on inside, need to monitor, or a certain temperature... (plants?)
I hope then you would have:
1. Programmable thermostat to set temperature versus time.
2. Maybe a remote IP camera to take a peek inside your house, maybe with a timed light. ZoneMinder is a great piece of software to use with that.
3. There are several temperature sensors you can get, but if you are a HW geek you could check out integrating a kit from Maxim: http://www.maxim-ic.com/products/ibutton/products/ ibuttons.cfm#sensor

-Ho

Unfortunately, it used a funky "One Wire" adaptor to get power and talk to a PC. If only they would reintroduce it in a USB format!

They do sell USB adapters for iButtons - see http://www.maxim-ic.com/products/ibutton/products/ adapters.cfm. However it looks like the crypto iButton itself has been discontinued. I hope that someone does release a similar product in the future, before the battery dies in the one I am currently using.

In almost all modern motherboards, the CPU power is derived from the 12V rail.

The reason is that CPUs require about 50-100W, at very low voltages (~1V). Taken direct from the power supply, you'd need cables capable of carrying 50-100A, which would be a *lot* of copper, and still waste a lot of power through I^2R loss. At 12V, you need to carry only about 10A max, which is easy for inexpensive cable and connectors. Another reason is that the DC-DC converters that generate the CPU core voltage are more efficient when running from higher supply voltages.

This is also why you wouldn't want to run your server rack off 12V or 5V power, the losses in long wires will generate a lot of power wastage through heating. Telecom equipment has, for years, been powered by a -48V DC rail, this is a convenient voltage (multiple of 12V, so battery backup is easy), not high enough to kill you if you touched the wires and not low enough to cause losses to mount. Unfortunately, modern, cost-effective semiconductor processes won't work well at 48V (you need specially constructed chips), so the cost stays high.

Many folks said that RS-232 requires +/-12V. True, but only a few milliamps on each rail. Typically, you'd use a charge-pump inverter to generate these voltages. More mysterious is the -5V rail, these used to be required by *really* old dynamic MOS chips, as well as some types of EEPROM and Flash, but not any more. Why is it still included in the ATX standard?

Like you said, pick your hardware carefully:
http://www.maxim-ic.com/quick_view2.cfm/qv_pk/1798
It has an internal 5 volt to +/-12 volt converter.

11 GHz chip != 11 GHz processor. They're mainly talking about analog chips - i.e. op-amps, oscillators, high speed muxes, etc. Chips like these: http://www.maxim-ic.com/solutions/cellular_handset s/index.mvp?pl_pk=14 http://www.analog.com/en/subCat/0,2879,770%255F851 %255F0%255F%255F0%255F,00.html

I licked quite a bit of the microcontroller-based embedded design, and from what I saw, only amateurs, and only most clueless of them use separate processor and controller. In the past it was making sense. Nowadays the market is saturated with microcontrollers that carry enormous amounts of extra hardware on chip and a hour with soldering iron spent on including a dedicated controller chip in the project can be easily avoided by a hour of browsing the catalogues for derivative that has that controller on-chip. Price increases are often negligible. Speeds are amazing.

www.fairchildsemi.com/products/micro/ - SOIC-8 package, the size of an optocoupler - 8 pins, thingy would fit on the nail of your pinky, whole, with surface-mount pins. 64 bytes of RAM, 1-2K of program eprom, 64 bytes of data eprom, clocks, power monitoring, wake-up on any pin, 6 GPIO lines, eeprom writing, watchdog, serial output generator, sleep mode, idle mode, oscillator, and quite a few other goodies.

On the other end of the scale: http://www.maxim-ic.com/quick_view2.cfm/qv_pk/4535 : 75MHz 64M addressable, ethernet, 1w, spi, CAN, 3x RS232, 8x bidi 8-bit GPIO, IP stack plus UDP, TCP, DHCP, ICMP, TFTP, IGMP in ROM, Wake-On-Lan, watchdog, clocks, and God knows what more.

Add to that DSPs which are quite specific but achieve speeds higher than newest pentiums and athlons in their tasks (and often carry some "extra", add PC for heavyweight number-crunching and user interaction and you see:

Controllers are dead. Microcontroller is way better because it allows for just the same on the hardware side, while vastly simplifying the interface side. With your current knowledge you should catch up and learn microcontroller-based design pretty fast.

Here's a better one - 0.7 to 5.5V input. This would allow use of 87% of the battery power.

Dallas (now part of Maxim) has been doing this kind of stuff for years with their DS5002/5240/5250 series CPUs (http://www.maxim-ic.com/products/microcontrollers /secure/). Of course these are 8-bit devices that are used primarily for Pin-pad type devices at the Point-of-sale.

Yep, usually they are. It prevents a paperclip jammed in the connector from damaging or shutting down your whole computer. Here's an example part to do that

There's a problem: Macrovision. They deliberately put high-voltage pulses in the vertical retrace interval of some frames to confuse the automatic gain control in the recorder. The AGC sees the spike, winds the gain down and you get a dim picture for several frames. Then it goes bright again. Then they put in another spike and it goes dim. As far as protection schemes go, this one is totally christian. You will just need a DVD player with the option to disable Macrovision; a VCR with RGB inputs; an RGB to composite encoder {NB; must be the appropriate video standard, PAL, SECAM or NTSC, for your region}; a timebase corrector; or an image stabiliser.

One very simplistic way to defeat Macrovision is to build a simple level-limiter circuit, so the extraordinarily high voltage pulses sent in the vertical retrace interval will be clamped to peak white level {1V} before they reach the VCR. This is really nothing more than a DC-coupled, non-inverting, high-bandwidth version of a guitar distortion pedal.

To build a more sophisticated timebase corrector, use a 1881 sync separator to get the timing signals, and some sort of bilateral switch {a 4016/4066 will sort of just about do, but look at the Maxim web site for some higher-bandwidth, lower-on-resistance ones} to switch between the existing video signal, and a locally-generated "black" signal {about 0.3 volts}. The 1881 has a composite sync output which should be used to add "clean" timing to the artificial black {just force it down to 0V when the timing signal goes low}. Be sure to use op-amps with a decent slew rate, not 358's! You will also need either a bunch of TTL ICs {if you're hard} or a microcontroller. At the beginning of each frame, switch to "artificial black" for about the first 20 lines of picture, then switch to the real picture for all but the last 20 or so lines, which should be replaced by more artificial black. You may need to experiment with the number of lines you strip out. If you are 500p3r l33t, you might even care to insert your own locally-generated Teletext information in the newly-created vertical retrace interval; but don't expect this to come out right on a VHS recorder.

A QuickChip uses an uncommitted array of strategically placed devices that you can quickly interconnect to meet application requirements (similar to gate arrays for digital designs). Because there are fewer masks to customize, QuickChip arrays are easier to use, less expensive, and less time consuming than full custom design.

You want stable, filtered 12 volts from it? Go to Maxim, get yourself an inductor-based regulated DC-DC converter chip, some decent sized filter capacitors on both sides, and you're set. But you're still better off with lemons. And I'm no biochemist, but I'm guessing the tree's not going to like having its sap chemistry messed with, either. At the very least, I imagine you'd deplete the electrolyte around the aluminum electrode and it'd stop working. Maybe there's enough flow in there to keep the circuit going, but again, it's going to be doing something funky to the tree if there's any significant chemical process going on.

And then there's the guy's initial assumption - that because lighting can go from the ground to the sky (sort of), there must be some sort of energy in the earth. Maybe if the Kansas Board of Education has their way, we can ALL achieve this level of scientific insight someday!

1-Wire API for Java Software Development Kit
http://www.maxim-ic.com/products/ibutton/software/ 1wire/1wire_api.cfm

and here's the lowdown.

First, nowhere is it stated clearly, but I'm fairly sure they're not talking about inkjet cartridges but laser toners. These are the ones I code replacements for.

The chip in question is the Dallas-Maxim DS2432. It's an EEPROM with a twist: it uses some cryptography to perform authentication.

The idea is that the master (in this case the printer) and the memory can negotiate a shared key, which is done in the factory or during testing -- the chip doesn't use public key encryption, so it requires a key exchange `in the open' which must obviously be done before the chip reaches the customer. (Lexmark has done some ugly implementation mistakes in some printers but nothing THAT bad.)

So this key allows authentication of both the printer and the memory. After an authenticated read, the memory must compute a hash of some data (including a nonce and the last page read) and send it to the printer. If the hash matches what the printer was expecting, the printer is sure that the memory knows the shared key. (Unless stupid implementation mistakes are made that open the way for replay attacks.)

Conversely, when the printer asks the memory to commit a write, the memory requests a hash as well, to authenticate the printer. You may ask, `what's the point?' This memory holds data on how many copies were made, serial number and so on. If the memory just blindly wrote what it was told, remanufacturers could keep resetting the contents and reselling the cartridge.

So how do you build a replacement chip? Easy, get the key somehow and implement the protocols used by this memory on a microcontroller. Using an off-the-shelf DS2432 is impossible because these things have serial numbers with a fixed byte (the `family code') which is different from the same byte in Lexmark's DS2432s -- they probably buy so many of them that they were in a position to ask Dallas-Maxim to make batches of chips with modified family codes. A little bit of security by obscurity, but that wasn't a barrier to us -- it took less than a week to reimplement (in assembly) the DS2432 protocols on my favorite microcontroller architecture, the Texas MSP430.

Now, I don't like to get into the politics of this thing. Myself, I believe what I'm doing is perfectly fine and in fact the right of the consumer, EULAs and contracts and patents be damned. I wouldn't do it otherwise. Some people complain that Lexmark sold a discounted toner (called Prebate), on the basis that you would return it to them, and you didn't, and that's unfair. What they don't take into account is that your printer comes loaded with a Prebate cartridge, and with a small amount of toner to boot. Many if not most people just use this one cartridge that came with their printer, and keep remanufacturing it. The customer didn't have a choice in this -- if Lexmark offered a regular toner, or no toner at all, when the customer bought the printer, the situation might be less clearcut. As it stands, I see this as Lexmark forcing everyone to pay for a crippled toner, giving them no choice in the matter, and so they're perfectly justified to remanufacture it. (This might not be considered ethical by some, and is most probably illegal, but I don't care.)

Moreover, the prices they charge are completely absurd. I know this is standard practice in the industry, but I consider this highly immoral. Very few companies possess the technology to make a printer, but many possess the technology to remanufacture toners and cartridges. By imposing legal and technical hurdles on remanufacturing, printer makers are effectively enforcing a monopoly, and the worst thing is, some courts are sanctioning this monopoly. The traditional analogy with auto parts holds very well, and many other frightening scenarios haven't been explored -- what if the printer makers agree on a policy of no longer manufacturing toners and cartridges for printers older than 1 year so as to force everyone to upgrade and m

It's usually not. Crystal oscillators have some temperature dependency, and this is a major reason PC clocks drift in an inconsistent way. A 10 degree C temperature change typically results in about a minute of clock error per month. See "Crystal considerations for Dallas real time clocks

Yes... If they only made bigger capacity versions of iButtons.
Great stainless, Fire-proof, acid-proof, frost-proof, smash-proof, EMP-proof, and a few others-proof, likely to survive nuclear explosion with just a bit of shadow to protect it from evaporating, guaranteed to operate in quite harsh conditions, size and shape of a bigger watch battery, rather inexpensive, shiny, reasonably fast, comes in password-protected versions, easy to interface (just touch the reader)...
Superb, wonderful indestructible data storage. Whole 8 kilobytes of it.

http://www.maxim-ic.com/alternatives.cfm/part/BQ48 22/pk/81

Take out the battery for 10 years?
Most likely upon detecting clock skew it will cancel your key immediately. And most likely they have their ass covered by license in case this happens accidentially.

I agree, if someone wants that implant, it going to hurt, but they will get it.

Also, it can be copied.
I mean, just how easy would it be to get the tag id and copy it.

Having a short range is not a defence, the whole point is he want to use it, therefore other systems must be told about it.

I think products like this have more potential.
http://www.maxim-ic.com/products/ibutton/

That said, I applaud his 'just do it' attitude.
Though, these are basically the same things that I have impanted in to my cats, so really there is little risk.

Why is implanting into a human so news worthy, lab animals have these tags implanted all the time, and taken out and resused too.

I wondered that myself, given how cheap iButtons are. Several mounting options are also available.

I wondered that myself, given how cheap iButtons are. Several mounting options are also available.

a: For the wired version: Support for Power over Ethernet. This way, separate power isn't needed in many installations.

The development board and DCME itself break out pins from the PHY for this purpose. No problems here. You just need to hook up something like a MAX5941 and you're set. (I haven't been interested in this yet, tho.)

b: A single USB port for both versions

The FTDI FT232BM is what you're looking for. RS232 to USB, with drivers for Windows, Mac, and a linux usbserial driver to boot. $5/chip in one-offs. Great chip for interfacing with any serial device, microcontroller, etc. Mouser sells this chip on a nice backpack board with all the external logic you need -- just connect the power, tx, and rx, and you're done!

Of course, this won't get you USB HOST (which is probably what you want), so in that case you may have to pursue another design.

And here - IBM Research - PAN
And I'm pretty sure I read about it on Slashdot at the time, too, but darned if I can find it in a search now.

Is NTT just sooo big that they can take on IBM in a patent fight; or is it a cross-licensing deal?

I can think of a lot of applications for this if they can get it to fit into a Java Ring...

They seem to work great, at least in the few places where I've seen them in use. The users, who don't understand security, think that these devices are a bit weird of course, but it doesn't matter. They get along fine, treating them like the keys to the office, which they are, in effect.

WRT to F/OSS, these are hardware devices. What you really need is a free reference design.

You could sorta fake it, but it wouldn't be the same. For example, suppose you kept GnuPG keys stored on a USB key fob. Then you encrypt the keyring with a simple password. Voila -- two factor security.

The only problem is that the key fob has to trust the computer it is connected to, because it is going to hand over the secret key to it. If they computer is compromised -- that's it.

What you really need is a device with its own computing power, such as an iButton. You then have software which sends a challenge from the server to the iButton, calculates a hash, then calculates another hash on that hash using standard password techniques.

The password of course would be very little addditional protection, but very little is needed. What you want is to buy a few hours of protection after you lose your device to notify the network administrators and get your account locked out.