Equipment you carry daily?

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Bogo said:
I've been looking at the much to large plastic handle to my flint. I just took my knife to it and whittled down the plastic to a much more respectable 5/16" thick over where the flint is in the middle and nearly totally carved away at the middle edges. I must have removed over half the plastic handle. When I reshaped it I carved scalloped curves into the faces at the edges to provide a better grip. I should get the V gouge out and put some hatching lines across the faces for an even better grip.
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Pictures?
 
VanGo said:
RF Radio Frequency ID theft? Is this it Dan?
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Exactly. Many new credit cards and all new pass ports have passive RF transmitters in them. When they get in a RF field they transmit data using the energy from the Rf field as a power source. It's very easy for someone standing next to you to read the cards in your wallet or purse.
 
rusty_tlc said:
What are you guys using to stop RfID theft?
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I have one card that is RFID. I keep it in it's own wallet with sheets of ferrous metal on both sides of it. My cattle ear tag RFID reader can't even see it when placed directly on top of it. RFID used for security really needs to have some sort of cryptographic security for the communication. A vast majority doesn't.
 
Bogo said:
I have one card that is RFID. I keep it in it's own wallet with sheets of ferrous metal on both sides of it. My cattle ear tag RFID reader can't even see it when placed directly on top of it. RFID used for security really needs to have some sort of cryptographic security for the communication. A vast majority doesn't.
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I'm thinking a thin piece of copper clad PCB material, maybe .015" thick, cut to the same size as a credit card would do a fine job.
 
rusty_tlc said:
I'm thinking a thin piece of copper clad PCB material, maybe .015" thick, cut to the same size as a credit card would do a fine job.
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It must be a ferrous metal. Something that a magnet will stick to. I scavenged my from the plates used in a big transformer, but nearly any ferrous metal should do.

Edit: RFID powers the chip on the card electromagnetically via a loosely couple transformer. One winding of the transformer is the antenna, and the other is on the card. The activating transmitter generates an alternating electromagnetic field which is received by the receiving transformer coils on the card. You need to block that reception. Once that is blocked, the chip has no power so it can't operate transmit it's contents. For self powered chips it is different, but they can't put them into credit cards yet due to lacking battery technology.
 
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Bogo said:
It must be a ferrous metal. Something that a magnet will stick to. I scavenged my from the plates used in a big transformer, but nearly any ferrous metal should do.

Edit: RFID powers the chip on the card electromagnetically via a loosely couple transformer. One winding of the transformer is the antenna, and the other is on the card. The activating transmitter generates an alternating electromagnetic field which is received by the receiving transformer coils on the card. You need to block that reception. Once that is blocked, the chip has no power so it can't operate transmit it's contents. For self powered chips it is different, but they can't put them into credit cards yet due to lacking battery technology.
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Why a ferrous metal?
 
It needs to even out the magnetic waves passing though it. It is a mini Faraday cage.
 
What are you guys doing to protect against RFID theft. I was on post yesterday and oddly enough could not find any solutions or products to address this need?
 
rusty_tlc said:
What are you guys using to stop RfID theft?
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i like most of north america am being pro-active against rfid theft by ruining my credit so when "they" steal my id the credit agencys will have a new victim to harass, because i belive in cruel and unusual punishment, jk :D
 
Bogo said:
It needs to even out the magnetic waves passing though it. It is a mini Faraday cage.
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They aren't reading the magnetic strip.
They are reading the passive RfID chip which some companies now use. This is an IC which is powered by an antenna that also acts as an inductor. When the correct frequency is received by the antenna it converts the incident RF energy into electricity which powers up the IC, which in turn transmits data back through the antenna. This all happens at radio frequencies, as near as I can tell anywhere from a few hundred Hz up to several MHz.

I design RF shields for the products my company builds. The goal of the RF shield it stop stop unwanted emissions from our product and block outside signals from interfering with our circuits. We use a alloy 770 for our shields, this is a mix of mostly copper with some zinc and nickle added in. You probably already know that copper+zinc = brass, the nickle gives the alloy a nice silver color and prevents tarnish. A simple piece of copper printed circuit board that you can buy at Radio Shack will work fine as an RF shield. Just cut two pieces about the size of a credit card and put one on each side of the credit card stack in your wallet. Brass shim stock would work fine too. I like the PCB idea because it has a little flex to it but isn't likely to bend.
 
rusty_tlc said:
They aren't reading the magnetic strip.
They are reading the passive RfID chip which some companies now use. This is an IC which is powered by an antenna that also acts as an inductor. When the correct frequency is received by the antenna it converts the incident RF energy into electricity which powers up the IC, which in turn transmits data back through the antenna. This all happens at radio frequencies, as near as I can tell anywhere from a few hundred Hz up to several MHz.

I design RF shields for the products my company builds. The goal of the RF shield it stop stop unwanted emissions from our product and block outside signals from interfering with our circuits. We use a alloy 770 for our shields, this is a mix of mostly copper with some zinc and nickle added in. You probably already know that copper+zinc = brass, the nickle gives the alloy a nice silver color and prevents tarnish. A simple piece of copper printed circuit board that you can buy at Radio Shack will work fine as an RF shield. Just cut two pieces about the size of a credit card and put one on each side of the credit card stack in your wallet. Brass shim stock would work fine too. I like the PCB idea because it has a little flex to it but isn't likely to bend.
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I understand all that and I understand the magnetic strip is not involved in this at all. I've made my own low frequency passive RFID tag readers from TI modules*. When I tested out how to block them, I found out that it was much more effective to keep the RFID tag in the "dark" so it never powered up. To do that I found out I had to magnetically shield it. A well formed aluminum foil shield could keep the tag's transmissions from being read, but it couldn't stop it from powering up. Cut a small hole in that foil shield and I could read the tag. Sure the read distance was lowered, but it was still readable. When I tried the two transformer plates, I stopped being able to read the tag. When I stuck a small antenna loop from a RFID reader set to passive mode in the sandwich I couldn't get a read when the other reader was trying to read it. The nice thing about the transformer plates is I didn't need them to have 100% coverage like the aluminum foil needed. They only needed to cover a slightly larger area than where the antenna on the card was.

* 10 years ago cattle RFID tag readers were $1,500 minimum for a dumb one with no display. TI RFID modules from DigiKey could be had for $75 each. All you needed to add to the module was a serial port level translator chip, antenna, and power supply. Then a PDA with a custom application on it could talk to it.

BTW, many car keys now have RFID tags in them.
 
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