How well does the Android NFC API support Mifare Desfire?

Question

I\'m likely to be working on a project where existing Desfire cards (used to access paid services) will be replaced with an NFC-capable mobile device. Can anyone point me to

Answer 1

MIFARE DESFire is ISO 14443-4 compliant. Support in Android for ISO 14443-4 (and therefore MIFARE DESFire) is done by the IsoDep class. You can send any DESFire command using the transceive() method of that class.

Besides that, DESFire can be configured to be NFC Forum type 4 Tag compliant. In which case Android will read out automatically any NDEF messages from the tag and dispatch it in an intent. So you can make your app start automatically when a specific tag is scanned. (Android can also format a DESFire chip to contain NDEF and write NDEF data to it.)

Replacing a DESFire card by a mobile NFC device is another matter. Card emulation on currently available Android devices is done by an embedded Secure Element connected to the NFC chip. An Android app cannot emulate a card (there is also no API for this) and the Secure Element cannot emulate a DESFire chip. Furthermore, there is no open API to access the Secure Element from an app.

The only way an Android NFC app can communicate via NFC to another device (that is not a card) is using Android Beam. This is, however, a different protocol than that used between card and reader.