What is a RFID?

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Forum topic by HallTree posted 04-02-2009 07:11 AM 1864 views 0 times favorited 9 replies Add to Favorites Watch
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5664 posts in 3764 days

04-02-2009 07:11 AM

I recently read a very interesting article on Radio Frequency Identification (RFID) tags.
RFID’s are fast becoming a means of identifying just about any material object. You probably have been using them. They are used on pet ID tags or under their skin, on EZPass through a toll booth, paying for gas, tagging flight bags, used to track shipping containers, employees ID tags, drivers’ licenses, they are on all new issued passports. They can be incorporated into cell phones and other devices. Thus, you could pay for parking, buy a newspaper, or grab a soda from a vending machine without opening your wallet. They are very small. The new ones are as small as the dot at the end of this sentence. They are considered as the next generation barcode. A barcode must be read directly by a scanner without anything in front of the barcode. RFID’s can be read through most materials and can be applied to objects in harsh environments, are maintenance free and will last for years. They just set there dormant until a radio signal wakes them up and requests an answer. Some of them are designed to be read within a few inches, some several feet away.
What is in the future for RFID’s? Plans are to place them into all sensitive or important documents such as paper money, stock certificates, manuscripts, university diplomas, medical degrees, auto tags, birth certificates, and any other sort of document you can think of where authenticity is paramount. Who knows, someday you could put one on that project you sold that you made in the shop.
Consider the human body. There is now a RFID that is designed to go under the shin. It is a great way to keep track of children, Alzheimer’s patients, mental patients, prisoners, or other persons in danger of wandering.
This is all very good and will make our lives a lot better and secure, but it gives me the creeps. The possibilities are scary. Anything our government or companies obtain from RFID’s can also be obtained by the bad guys. For around $150, a person can buy a RFID reader that can activated a tag, within your billfold, from 4” away.
It’s something that I am going to have to live with, like it or not. Sure, it’s possible to destroy a RFID tag. There are web sites on the internet that tells how to crush it with a hammer, puncture it, or even microwave it, but that would also probably damage what it is in. I can’t drown it or demagnetize it. And washing my clothes, that have a RFID tag, won’t remove it. I could remove it, but first I would have to find it.
Congress could pass a law requiring that the consumer be notified about products with embedded RFID tags. We should know when we are being tagged. We should also be able to disable the tags in our own property. If it’s required by the company we work for, that’s a different matter. But if it’s ours, we should be able to control whether tracking is enabled. I do not think that will happen. They, and you know who ‘they’ are, would like to know who we are and where we are.
There is one thing that I can do. I found a few web sites on the internet that sells a billfold, about $20, that is made to block RFID’s. At least I can protect that information.

-- "Hold on to instruction, do not let it go; guard it well, for it is your life" Solomon

9 replies so far

View Chris 's profile


1879 posts in 3987 days

#1 posted 04-02-2009 01:58 PM

Dave, possibly… However a Mu shield works to block EM radiation; so a copper mesh would be far more effective. Where do we stop?

-- "Everything that is great and inspiring is created by the individual who labors in freedom" -- Albert Einstein

View Derek Lyons's profile

Derek Lyons

584 posts in 3564 days

#2 posted 04-02-2009 07:21 PM

As far as I know:

Before you go getting all paranoid – keep in mind that RFID tags intended for reading at any distance (more than a yard or so) are pretty good sized. (Think around the size of a matchstick or a little larger.) So they aren’t actually very easy to hide. The (current) practical limit for reading distance is (IIRC) around 9 or 10 feet – not very practical for tracking people except when you know the person of interest will pass near a particular point. (Like Alzheimer’s patients.)

The ones that are relatively easy to hide, around the size of a match head or smaller, can only be read at distances from a few inches to a few feet. (Less than a yard or so.) Great for tracking items that might be shoplifted, but virtually useless for tracking individuals unless you know they are going through a certain door.

The ones that can be easily embedded in paper documents can only be read at distances measured in millimeters at best.

Now, on all of these, you can increase the distance they can be read from by increasing the power of the excitation signal and increasing the size of the reception array – but the square power law dictates that these get pretty big, pretty fast.

A friend of mine, who works on such things, recently estimate that reliable tracking on the order of a mile or so would require a transmitting and receiving array around the size of a two story house – and would emit so much RF energy as to fry any unshielded electronics within a couple of hundred yards. Needless to say, such a thing would be pretty hard to hide.

To completely and reliably block RFID tags from being read – you need a Mu shield or a Faraday cage, both of which are somewhat difficult to maintain and easy to damage thus destroying their shielding ability. I suspect the sites selling wallets that purport to block RFID readers use a considerable quantity of snake oil in tanning the leather they use to make the wallets.

-- Derek, Bremerton WA --

View Bob #2's profile

Bob #2

3809 posts in 4018 days

#3 posted 04-02-2009 09:36 PM

James Orwell must be smiling from the space ship right now.


-- A mind, like a home, is furnished by its owner

View HallTree's profile


5664 posts in 3764 days

#4 posted 04-03-2009 03:09 AM

Interesting comments guys. Here an interesting short video

-- "Hold on to instruction, do not let it go; guard it well, for it is your life" Solomon

View HallTree's profile


5664 posts in 3764 days

#5 posted 04-03-2009 03:16 AM

If you don’t want to buy a RFID blocking billfold, you can make one. Red Green would love this. Click HERE.

-- "Hold on to instruction, do not let it go; guard it well, for it is your life" Solomon

View kiwi1969's profile


608 posts in 3438 days

#6 posted 04-03-2009 04:15 AM

This is alien technology being used by the UN, who are actually lizard creatures in disguise seeking to subjugate us! Prince charles is their leader!

-- if the hand is not working it is not a pure hand

View John Gray's profile

John Gray

2370 posts in 3882 days

#7 posted 04-03-2009 04:22 AM


-- Only the Shadow knows....................

View TomK 's profile


504 posts in 3871 days

#8 posted 04-03-2009 05:34 AM

This thread made me expect a photo of Odie with an aluminum foil cap!

Derek is right. At this time, RFID, for economic and range reasons, is only practical for tracking pallet sized items in a warehouse enviroment.

-- If you think healthcare is expensive now, wait until it's free! PJ O'Rourke

View Tim_456's profile


170 posts in 3592 days

#9 posted 04-07-2009 04:01 AM

It’s always a controversial issue regarding personal privacy versus what the goverment knows, but keep in mind that the government already knows what you make per year from your taxes and could determine what you spend based on the difference between your income and your savings and major purchases (house, car, etc) which are all tracked through sales tax and licenses. As for the hundred or two in your wallet, that’s small potatoes and largly irrelevent. The one thing you can count on is that 99.99999% of the individuals are, on their own, insignificant. No one likes an invasion of privacy and tracking, but anything “interesting” that one might do is overshadowed by the mass of uninteresting mundane and routine activity. Your normalcy will shield you;) I speak also as one that’s insignificant.

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