Check Key with Mfcuk

[cenzo85]

Hi all,
I want try to use this tool in order to recover a key form a Mifare card.

My card have the first 10 sector setted with key A / B "ffffffffffff"

So, now using the comnand:
mfcuk -C -R 0 -d ffffffffffff -v 3

I'm aspecting to receive an immedite confirmtion of the key...
BUT,
the tool not identify the key and continue to execute an infinite check.
The log write me:

`

Let me entertain you!
uid: 8f008a4b
type: 08
key: 000000000000
block: 07
diff Nt: 1
hit4: 0
auths: 7

---

Let me entertain you!
uid: 8f008a4b
type: 08
key: 000000000000
block: 07
diff Nt: 1
hit4: 0
auths: 8

`

In my mind I would aspected the the key will change every time..
But actually I see that the system check every time the key 000000000000
And this is confirmed because no key are found

I have note the also by using:

mfcuk -C -V 1 -d ffffffffffff -v 3

the system respond me:
Key A sectors: 0 1nfc_initiator_transceive_bytes: Mifare Authentication Failed

Could some on help me to undestand how it work ?