Is it possible to Write two different NFC UIDs to one single NFC card?

NFC
#1

Hi,
Is it possible to Write two different NFC UIDs to one NFC card?

For example, if I scan my home NFC key and my work NFC key, I will have 2 NFC keys in my flipper zero.
Can I write both NFC keys to one NFC card so I can use one key instead of using two to get into home and work?

#2

There is multi-fobs at aliexpress. It has multiple t5577/s50 chips inside one case with buttons.
hold button 1 - write/emulate card1
hold button 2 - write/emulate card2
…
https://www.aliexpress.com/item/3256805270664891.html

1 Like
#3

Very interesting.

#4

The Chameleon Ultra got 8 dual slots (one for HF one for LF on each position).
Unfortunately the Firmware is really at the beginning, through the new nRF reader it is really fast, but not such mature tested/implemented like the Chameleon Tiny or any Proxmark3.

How fast? For example nested attack:

  1. When the Flipper is calculating the missing keys for my old workspace access card, it calculates approx. 27 minutes, connected to a python capable PC.
  2. The Chameleon Ultra does the same embedded in less than 20 seconds.
1 Like
#5

I don’t want to have a keyfob, I want a wristband I can wear and get into home when I want.

How about this product? Can I write my home and work NFC key so I don’t need two of them, I just can use one.
Product:
https://www.aliexpress.com/item/1005003007367252.html

#6

AFAIK the answer is “No”.
One chip = one card = one uid.

#7

Funny that you mention wristband. So I come back to the Chameleon Ultra: Chameleon Ultra watchband case (incl. covert option) by LegendofTHIEF - Thingiverse :slight_smile: