[LINK] Industry Reply on e-Passport Cloning

[Adam Todd]

At 03:16 PM 12/08/2006, Geoffrey Ramadan wrote:
>Adam
>
>1) e-Passports use Near Field electromagnetic properties (i.e. it is not 
>like a radio transmitter which uses Far Field properties, but works like a 
>transformer which uses inductive coupling). The Near Field boundary is 
>defined at  Wavelength/2xPi  @ 13.56MHz this is about 3.52M  This defines 
>the theoretical maximum for which this effect works.

Gee did I say 4 meters in my message or what?

>The actual distance is dependent on the geometry of the antenna 
>(inductance and other factors) and how much energy you can transfer to the 
>tag. Noting that the Power the tag receives is dependent on how much 
>"flux" it can collect (i.e. area), which is required to power the tags 
>microcircuit (hence setting a min requirement)

Yes like listening devices that have an inductive receiver in the 2Mhz 
range, the more power you beam at the listening device over whatever range 
you can beam it, the stronger the transmission output.  A nice little 
capacitor could hold a charge for a short time, depending on the design of 
the device and how active or inactive it is.

Same principals apply.  I am VERY familiar with "wake up and talk" devices, 
in more areas than just listening or rfid.

>A very simple approximation is that max read range is fixed by the size of 
>the antenna. However, as shown above, the size of the tags antenna is also 
>important (greater distance less flux/energy)
>
>Translation: small antenna tag, small read range.

Yes generally speaking, but then the laws of physics can always be 
manipulated using techniques that break the rules.

>The best I have seen @ 13.56MHz RFID is an antenna frame (which you can 
>pass through) the size of a small shed, able to read tags that are 30cm 
>square at about 2 meters. The tags had also been specifically designed and 
>tuned for this to work

I've tested tags that are 5cm in size from distances of 8 metres, 
transmitting data from a Dallas One Wire memory chip.

>I would conclude that it would be impossible to read the e-Passport tag at 
>any significant distance, and certainly not at 4m. It would be interesting 
>to see how well a tunnel reader would work though!

Nothing is impossible, it's a matter of how difficult.

In todays era, it's not about difficult, it's about how persistent and 
desperate.


>2) Also the passport has in a metal thread embedded into one of the pages 
>(forming a ground plane). If the e-Passport is closed, it would be 
>impossible to read.

I wasn't aware this was included now.  In any event, I did say, reading the 
passport at a checkpoint.  Not something impossible to do.

In fact I'm working on a commissioned project presently that uses a PDA for 
this very purpose.  I'm suppose to prove it can't be done, however, given a 
laptop and some copper wire and a few Jaycar components, I've proven I can 
at least do it in a cumbersome form.


>3) As pointed out before, even if they did copy a e-Passport, I believe 
>this will make it easier to catch the fraudsters.

Actually I think it will only create confusion.  Who is the fraud!  The 
Authorities can't get it right presently, well in my personal experience, 
and that's growing in vast events.

I think sometimes we get too caught up with what's in the box and not what 
is outside.  Maybe that's why I now enjoy film making more than before - 
the challenge to make a proper that works, that doesn't really work, but 
looks like it does, without spending a defence budget on R&D to make 
something that isn't real.

Inspirational is the minimum I get out of this work now.

I have to admit, all my electronic gadget props have a truth in function 
and will do a conceptual functioning of the requirement.