Alfred's Serif Users' Forums — Protect your contactless cards - what is an RFID card?

Re: Protect your contactless cards - what is an RFID card?

2022-07-02T18:57:07Z

I've actually wrapped some kitchen aluminium foil (baking foil) closely around a credit card sized bit of cardboard, and put one such each side of the bundle of contactless cards in my card "wallet". I hope that is sufficient protection, and that the exposed edges don't represent a hazard.

Re: Protect your contactless cards - what is an RFID card?

2022-07-02T13:02:03Z

I have a car with push button start, and keep the keys in a sicnal blocker pouch. However, having some interior house walls 2' (61cm) thick probably helps as well.

Re: Protect your contactless cards - what is an RFID card?

2022-07-02T12:41:29Z

I have my credit/debit card and similar in a little metal case - it holds up to 6 of them. Tucks nicely into my waist bag front pocket; quick and easy to get into and find the appropriate card. It is sold as a credit card protector so hopefully it has been doing it's job the past few years I have had it.

Protect your contactless cards - what is an RFID card?

2022-07-01T18:58:03Z

I came across this site which tells you how contactless cards and eg library book security tags work, and how to protect your cards from being accessed by criminals.

https://www.irda.org/what-is-rfid-block … is-it-used

I have carefully excavated some different library book security tags to extract the actual functional thin sheet (printed circuit) that does the job, Each has an aerial (antenna) coil and a two contact chip. I gather that the chip receives a signal from the interrogating transmitter, rectifies it to get sufficient power to run the chip which sends back via the same antenna a signal coded with the identifier ( a number ?)

It appears that the commonly found RFID frequency devices can be interrogated at a modest distance, and it is advisable to store bank cards between covers of an RF blocking material. My research some time back, and I think I may have posted in the old forum, showed that the majority of the blocking was done by reflection of the interrogating signal at the outer surface of a metallic sheet, and only in part by absorbsion within the bulk of the cover. It is possible that the blocking covers should be polished, although I am not at all sure about that.

I hope this post is informative and useful.