EEVblog #890 - ArmourCard Active RFID Jamming Teardown

What's inside the ArmourCard active RFID jammer for NFC contactless credit cards?
Does it work? Will it protect you from skimming?

Support the EEVblog through Patreon!

EEVblog Amazon Store (Dave gets a cut):

[mikeselectricstuff]

Also look at Guardbunny - a self-powered open source RFID jammer

[hopkinskong]

Pretty sure the micro is a STM8L, see the SWIM programming pin in the patent PDF.
STM8L151x2/STM8L151x3 have marking code "L526", so probably the micro used on the board is

UPDATE: L536 is STM8L151F3U6

[afitzy]

$0.15 per meter for Aluminum Foil at Coles. I noticed that the card in this video had a $58 price tag on it. That equals 386.6m of Aluminum foil.

[BoltClevo]

Wow, 58 bucks for one that will get smashed in wallet, or 0.01 bucks for a shite piece of foil. Hmmmm, let me think which one I prefer...

[RobinHilton]

Would have made more sense if the active jammer was actually a pocket/pouch that you slotted your card into. Then it'd have made more sense to have the touch sensor so that you'd hold it by that portion when performing a transaction.

[heckler]

You wouldn't buy one, but you bought the last one for the sake of the teardown.
Mission accomplished!

[shadowguidr]

Your videos give me heartburn. Every darn time I watch your videos I have to get a bowl of cereal half way through. :/

[jandljph]

Hm... I paid roughly 20 euros back in 2013 for a nice and solid aluminium card case, which actually reliably protects the cards from getting smashed in the wallet and will stop any RFID reader, forever and with no chances of a mess if the battery gets breached... 58 bucks (even AUD) seems awfully steep for a product like this, unless you expect to be able to run with the scare tactics. Then, again, if people really buy into the myths, they'll probably prefer the aluminium foil, both in their wallet and as a hat.

Oh, wait, no, I forgot that over the last couple of years there has been something of a bullshit scare about aluminium, too...

[JoshuaNicoll]

I love how they didn't think about an active NFC jammer nearby, did they think it was just a gimmick or something?

[teardowndan]

I'm surprised that thing needs a battery in the first place: it should be getting all the power it needs to do its jamming from the RFID field and its large antenna.

[TheEPROM]

Rather interesting. My dad has been skimmed twice on the London Underground.

[Zeatsov]

battery lasts 2.85 years in standby... the QC sticker said 2015... at least a year gone already also you said the POS box was located next to the card reader... so maybe take the .85 as well. not much for your 58 bucks lol

[carlranson]

Great stuff Dave. One thing I've not seen anyone address is how far away can you read the modulation of a valid scan. I.e. Could you passively scan the data from a genuine transaction from a distance and get usable info?

[PelDaddy]

I am all for the tinfoil hat (or in your wallet), but this seems redundant. Now a more powerful model that would work in a 2m or more radius would be a lot of fun to take to your local Starbucks...

[rsattahip]

I want an RFID blocker good enough for shoplifting. Wait a minute, I've been messing with electronics for 48 years, maybe I should build one.

[JerryWalker]

I suspect they are using a crystal as most low end micro internal RC oscillators do not meet the required accuracy specification for the protocol unless they are calibrated which is a pain to do on high volume low cost items. Probably cheaper to buy 1 million crystals rather than have to calibrate each unit. Power is unlikely to be an issue as the micro probably runs on an internal RC clock until it needs to modulate.

[alecjahn]

So it's like one guy trying to speak to you (RFID CC) and then another guy walking up, holding his mouth, and screaming (jammer)?

[nixietee]

For cards I do not intent to use the NFC, I used a strong flashlight to identify the coil. Then scratched a 3x3mm square with an exacto knife until i reached the coil layer and separated some of the strands. The cards don't loose other functionalities, like when frying it in the microwave.
Other cards are in a RFID sleeve from ebay. They work very well and you get a couple for a few bucks.

[laszlofabian]

The common attacks which can work on your NFC credit card are the relay attacks, the easiest way to protect yourself against it is to have 2 NFC enabled credit cards in your wallet. Since the anticollision is not allowed in the payment applications, so unless you take them out, you are going to be safe. Without any thin foil or any other jamming device.

[gblargg]

10:45 Feeling of shock as I almost thought Dave was going to decide to not tear it down.