Tin Foil Hats Anyone?
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https://rfidtag.com/does-aluminum-foil-block-rfid-signals/
I think mostly obvious information. LOL. For me, I am not too concerned (though I do have a fanny pack that I use when traveling that is supposed to block the signals, mainly for my passports and credit cards so no-one can read them. Maybe I am a bit paranoid. 555)
Can Aluminum Foil Block RFID Signals?
Aluminum foil is often cited as a simple DIY solution to protect RFID cards from unauthorized scanning. Its protective effect comes from basic physical shielding principles: aluminum is a conductive material that can reflect and absorb electromagnetic waves, creating a barrier that interferes with the RFID signal between a reader and a card.However, the effectiveness of aluminum foil depends heavily on the RFID frequency. High-frequency (HF) signals around 13.56 MHz, used by most NFC and contactless payment cards, can be partially blocked by foil, but low-frequency (LF) and ultra-high-frequency (UHF) signals may require thicker or multiple layers for noticeable attenuation.
There are also practical limitations when using aluminum foil:
Thickness and coverage: A single thin layer may not fully block signals; gaps reduce effectiveness.
Proper wrapping: Cards must be fully enclosed to prevent signal leakage.
Durability concerns: Frequent folding or bending can damage both the foil and the card.
In short, while aluminum foil can serve as a temporary or emergency RFID shielding solution, it is not the most reliable long-term method for consistent protection.
