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What this does is collect data from the reader that can be used to calculate keys that may unlock sectors of a MiFare Classic tag that would have access granted by that reader. Now, what can you do if it doesn’t know the correct keys for your tag? There is a tool for that too called “Detect Reader”. This process may work and it may not, it just all depends on whether people have added the keys used to secure your MiFare Classic’s sectors to the list that the Flipper uses. That is why these tags can take so long to read the Flipper has to try hundreds to thousands of keys on multiple sectors to try and copy all of the data.

What the Flipper does when you try to read a MiFare Classic is a brute-force attack on all the sectors by trying every key it knows about on each sector. Crypto1 has already been cracked which allows for some more advanced methods of duplicating a key, but that is not something the Flipper is capable of (at least not yet). MiFare Classic tags are not designed to be read by just any reader like NTAGs. Now, this sequence presents a problem for a Flipper (or any other reader not programmed for that key) to read and copy the data.

If everything is in order, the reader opens the door.

The reader validates the key and access conditions it receives and checks if the UID of the key is valid or within a specified range.

Assuming the MiFare classic is programmed for this door, it sends back the key and access conditions.

Reader detects NFC card and sends out information to unlock at least 1 sector on the MiFare Classic chip.

Each key in each sector can be used to open a door (or anything else) in a sequence that goes something like this: All of these sectors can be encrypted with the Crypto1 algorithm to protect the data from being copied. Each sector can contain 2 keys as well as access condition information. Like most, if not all, NFC cards it also contains UID and other data. The memory of this chip (assuming we are talking about the Classic 1K) is divided into 16 sectors of 64 bytes each. The MiFare CanaNFC-based NFC based chip following the ISO 14443A standard. (This is mostly a summary of info found here: and my knowledge of these systems.) Assuming you are talking about the key file for MiFare Classics, then yes, it is a brute-force LIST to be used by the NFC reading app.įirst, a little background on the MiFare Classics: