They Thought She Was Crazy: Doctor Extracts RFID Chip From Sex Trafficking Victim

a reply to: Bedlam

But your saying e fields get interfered with by tissue. Interfered like theres an impedance to overcome and the field getting also getting altered to semi useless by traveling through tissue?

How powerful of an efield would be needed to send a signal and would that be prohivitive due to the size of the device needed?

Im asking cause i dont know. But i like learning.

a reply to: BASSPLYR

E-field tags use propagating radio waves. You have several reasons why this is a bad idea in meat.

1) the tags use fairly long wavelengths. So the chip part may be small, but the total tag assembly is not. (it's the old radio antenna size is a function of frequency thing rearing its ugly head again) So e-field tags aren't the size of grains of rice.

H-field tags use fairly low frequencies, but it's magnetic, so you can put in a tiny bit of ferrite and a coil of wire, which is the gold color thing you see in a Digital Angel part. So even though an h-field tag might have an operating frequency orders of magnitude lower than a UHF tag, they're also orders of magnitude smaller because you don't have a propagating wave to interface with.

2) Radio waves have that pesky set of Maxwell's laws attached. The dissipation in blood/lymph/meat is directly proportional to frequency. So the higher you go in frequency to get the antenna size down, the worse the loss.

3) Radio waves have this annoying tendency to diffract and reflect. So at every impedance step you lose a metric crapton of the signal. That's air to skin, skin to subcutaneous fat, fat to muscle, muscle to tag on the way in, and then again at each step on the way out. So you lose close to all of it to reflection and diffraction. What you don't lose there you lose to dissipation. Radios buried in meat don't work well. This is directly analogous to the goop you use on ultrasound probes, by the way, and for the same reason. The goo is to reduce the impedance step between the transducer to air, air to skin, and skin to air, air to transducer on the way out. There's a reason they can't aim an ultrasonic scanner at you from across the room, and it's the same for burying e-field tags in meat.

4) The e-field tag itself uses something called quarter-wave backscatter. It doesn't transmit. At all. It takes some of the power from the e-field interrogator, powers up a very simple circuit that returns a serial number. It returns it by varying the reflectivity of the tag. In essence, the interrogator is a very simplistic radar that only works with tags. The tag essentially varies its RCS to return some of the interrogator's signal. In fact, the equation you use for e-field tags is the basic radar equation. However, when the thing's buried in meat, you have countless reflections on the way in and out, and the end reflectivity coefficient differential between the tag's mark and space states closely approximates to zero.

H-field tags use load signalling instead of quarter-wave backscatter. MUCH easier to detect close in. However, h-field has its own set of problems. The power density of the interrogator falls as the sixth power of the distance. And the load signalling is read as a differential load on the interrogator's output. The bigger the drive, the less the percentage change. There is a truly awful signal-to-noise ratio with h-field load signalling that's exponential with distance. Between the SNR, the signal return falloff and the sixth power distance problem, you can't practically read h-field tags at a distance. However, they're dandy for burying in meat.

More, since h-field tags only communicate in the near field, you can't read them outside the near field at all, because they don't use propagating waves. Like e-field tags, h-field tags don't radiate signal either.

On the other hand, in close proximity, you can couple a lot more power to the tag with h-field, which is why credit cards and passports use h-field signaling and not e-field - they've got little microprocessors in. H-field can get you enough power to run one, whereas passive e-field tags can't.

So h-field is basically weigand type technology in a proximity application. (correct?)

ETA...and yes, the work we do is generally with e-field type RFID.

Oh, come on, people! Doesn't ANYONE remember Revelation 13:17 - 'And he causeth all, both small and great, rich and poor, free and bond, to receive a mark in their right hand, or in their foreheads: And that no man might buy or sell, save he that had the mark, or the name of the beast, or the number of his name. Here is wisdom. Let him that hath understanding count the number of the beast: for it is the number of a man; and his number is Six hundred threescore and six. ' Some very powerful people would like very much for their biblical 'wet dreams' to come true as written.

Hint: RFID 'chips' or 'tags' have been used to track animals (beasts, in context) for many years. Very routine 'chipping' is done EVERY DAY at veterinary clinics and animal shelters. NOT for 'tracking', but for identification (thus the ID in R.F.I.D.)! As in 'Hey, we found that #### you lost!' So, track the AZ issued SSN 600-60-0006. It is a valid number, I've looked it up myself (the number of A man, not simply 'man'). Details are as important as a tiny o-ring in a fuel injector. Missing tiny parts, nothing works.

a reply to: Bedlam

Thank you sir for an excellent and educational reply.

originally posted by: WAstateMosin
Oh, come on, people! Doesn't ANYONE remember Revelation 13:17 - '...to receive a mark in their right hand, or in their foreheads'

This is the applicable part of the whole thing. Understand what 'charagma' means, and what a tefillin looks like, and why you might wear one, and you'll be a lot closer to understanding that chapter in context.

Exodus 13:9 - "And it shall be for a sign unto thee upon thine hand, and for a memorial between thine eyes, that the LORD'S law may be in thy mouth: for with a strong hand hath the LORD brought thee out of Egypt."

originally posted by: Flyingclaydisk
So h-field is basically weigand type technology in a proximity application. (correct?)

It's sort of a very very loosely coupled transformer with a huge air gap between the windings.

The tag uses a ferrite to "focus" extra magnetic field lines into the "secondary" - the coil inside the RFID tag - to increase the coupling a bit. Since you're just picking up magnetic field lines and not trying to catch a propagating EM wave, some of the bets are off. You don't have to match antenna size to frequency, and the magnetic field from the interrogator isn't strongly coupled to an e-field as it would be in a propagating wave. So, you don't lose the whole thing if the e-field component gets dissipated as you would in a radio based tag.

The tag signals back by throwing a small load onto and off of the secondary inside the tag. This varies the load that the interrogator's coil reflects to the output drive in the interrogator. That variation is pretty damned small. As the distance increases, the drive level you have to use to power the tag goes up as the sixth power of the distance, but the load variation simultaneously decreases as a percentage of the drive output, and also as the sixth power of the distance. This makes picking out the return more and more dicey. And outside a wavelength (more or less) of the signal, there's no return AT ALL, because you've left the near field. The tag's return only exists inside that diameter (the so-called 'lambda wall'). So, as small as it will be at the lambda wall, it won't exist whatsoever outside it.

That means that Superman can't read it past about 13 meters, even though you've practically lost the signal inside maybe 24" or so - I've seen a university manage a return that far away by using huge amounts of drive (several dozen Amps) and reading the tag thousands of times and correlating the returns with a DSP.

While these things do tend to have short ranges, there is tech now available which makes it possible to track an item like a small short range RFID.

How it works is you buy a tracker, attach it to an item you wish to locate if lost or stolen and uninstall an app on your phone or tablet. If the item is within range of your device the app will show it's location.

How it goes long range though is if you mark an item as lost/stolen, the tracker will register on any device it is near that has the app installed, so if the tracker goes past a phone with the app on the other side of the country you will be notified of it and where it was located therefore turning a small range device into pretty much a global tracker.

So it is not that far fetched to use a small chip as a tracker beyond what you would consider it's normal operating range.

In this case though I think it would be a good psychological tool and probably what it was used for.
Most people are clueless to the tech that they use and exists.
I imagine if you took someone, especially someone with zero clue about tech, injected them with a chip, then scanned it and showed them then informed them they were now being tracked and could be tracked wherever they were, you would have an effective tool to control somebody. That they would indeed consider it extremely likely they could be tracked and satellites were watching them.

Most humans after all are easily manipulated at the best of times. If you can control someone with words, then controlling them with tech illusions would be even easier.

But yes, as I stated at the beginning. The tech does exist right now and as more people adopt it the tracking network will grow bigger and people will abuse it as people always do when we invent things meant to better life, so it is something humans do really need to be worried about.

Only way to 100% guarantee privacy and not being tracked these days is to completely reject all forms of technology and run as far as you can from civilisation.

a reply to: AtomicKangaroo

So it is not that far fetched to use a small chip as a tracker beyond what you would consider it's normal operating range.

You are talking about devices which contain a bluetooth transmitter and a battery.

a reply to: AtomicKangaroo

You're confusing several very different types of parts that don't share a lot of anything except the umbrella term "RFID".

Bluetooth transponders with batteries in don't behave anything like passive h-field serial number parts, because the technology is totally different. So, yeah, it's not just far-fetched, it's not possible.

a reply to: Phage
a reply to: Bedlam
I'd encourage you both to read the entire post and think about the context of it instead of just one small part.


I do understand the differences between such items as tracker tiles and RFID chips but the point is we are getting to a place with technology when an item "LIKE" a small short range RFID (LIKE being the main word there) being trackable across a great distance will become a reality.
Just think about how many people you walk near every day who are carrying a blutooth/wifi enabled device. You would not need a large transmission range unless humans develop a habit of walking 200m from each other.
Also I mentioned other applications of an RFID like a psychological manipulation.

My thoughts being about looking at what currently exists as well as what could be very likely in a foreseeable near future.
If someone is is sick enough to rape or torture another person and implant a chip, it is not beyond reason that such a person would have no issue with embedding a stamp sized battery operated transmitter, especially if that tech is able to be further reduced in size at a later date.

I hope that clarifies things a bit for you both.

originally posted by: AtomicKangaroo
...but the point is we are getting to a place with technology when an item "LIKE" a small short range RFID (LIKE being the main word there) being trackable across a great distance will become a reality.

Except, as I said upthread, it's really friggin' awful trying to transmit from inside wet salty meat.

Getting them small entails using high frequencies to get 'small', as the antenna size is directly related to the frequency. And the higher you go, and the smaller you get, the worse the dissipation and reflection issues.

The little key fob Bluetooth devices last a year because they don't always transmit. They're in low energy receive mode most of the time, looking for a poll from a master device, your phone. Receiving doesn't take as much power by far. But you won't be able to receive all that well inside wet meat. Because the same issues exist on receive as on transmit. So you're going to have to transmit all the time. And since you will lose the vast majority of your transmit power in dissipation and reflections, you'll have to crank it. And that sort of obviates the use of low energy BT links. And small batteries. And short antennas.

There's a reason that submarines used ELF. And that the transmit antenna system took up most of a state, and millions of Watts of input power to get off maybe 8 Watts of emitted power. And that the subs had to use SQUIDS to receive the signal, or trail a line a hundred feet long. And it wasn't "wow, let's do something pointless and expensive", it was 'transmitting and receiving inside salt water is tough'. That's true regardless if it's an ocean or your butt. Saline has a path loss of dozens of dB per millimeter at the frequencies BT uses. It's not an option.

Implants don't tend to use radio waves. That's why you see these Verichip looking things that are purely near field and DON'T use radio waves - it gets them around the salt water issues. And you have the 'who will charge this battery' issues with your putative 'stamp sized battery operated transmitter', as it's not going to be low powered anymore.

Again - things that you implant inside people tend to not be qualitatively like things you attach to your car keys. You can't extrapolate from one to the other, because the technology that works in one case doesn't at all in the other.

tl;dr:

You can't slice someone open and stick in a Tile. It doesn't work that way.

a reply to: Bedlam

tl;dr I understand the tech, I work with such things every day, but I think you're missing my point, mostly in regards to the future not the present. So let's just agree to...not to disagree, but move on.

originally posted by: AtomicKangaroo

I think you're missing my point, mostly in regards to the future not the present.

I understand how Tile et al uses a sort of crowd sourcing to track short range transmissions.

The issue is that near field RFID doesn't transmit anything at all. And things that DO transmit propagating radio waves don't do much of a job from inside wet salty meat. So the vision of future crowd tracking using a sea of cell phones running an app or something similar is sort of..obviated.

And I don't just use it, I design things like it. Ta, then.