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I have some comprehension problems regarding the NFC Forum Type 4 Tag capabilities of NXP MIFARE DESFire EV2.

I found the NXP Application Note AN1104 regarding NFC Forum Type 4 Tag and NXP MIFARE DESFire EV1 and was wondering if the NXP MIFARE DESFire EV2 would also have the capability of acting as NFC Forum Type 4 Tag.

First a basic:

In theory when EV2 (or lets just take EV1 for this) would have the capability to act as an NFC Forum Type 4 Tag, would I still have the benefit of having mutual 3DES authentication and AES RF-encryption after the public NDEF transmission is send to the reader device? So the reader can access protected memory on the NFC tag only after authentication.

Second the issue:

Does the EV2 version have the capability of acting as NFC Forum Type 4 Tag at all? I could not find any mention of NFC Forum Type 4 Tag within the data sheets. Same goes for EV1 but there is the above mentioned application note for the EV1 which gives the impression that it is possible with EV1.

Some background:

I want to use an NFC tag for "no/low security" application. The "no security" application would basically be to read out the announced UID. The "low security" application would be to first read out the announced UID and after wards authenticate (view from the reader device) with the NFC tag, extract some kind of "day code" out of the protected memory and e.g. give the owner his/her desired drink out of the vending machine.

I want also discover some playground with Android devices. The NFC Forum Type 4 Tag will announce the public NDEF, an Android app starts automatically and handles the authentication with the NFC tag.

Bonus question:

Would NFC Forum Type 4 Tag (acting) raise any further security holes into the NFC tag?

Edit:

Or maybe my fundamental understanding of NFC Forum Type 4 Tag is wrong. What I think that I understand of Type 4 Tags:

  • Once they have a magnetic field to convert to electric energy they immediately start to announce UID and "special" public NDEF by itself.
  • Once e.g. Android receives the "special" public NDEF it will launch and associated Android application.
  • Further communication to the tag has to be fulfilled using IsoDep.transceive only.

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