I am studying about ISO7816-4 and I have a vague point in it. My question is: What is implicit DF selection? Please help me!!!
Depending on the card personalization, a DF different from the MF might be selected after reset. Implicit, because you don't have to send a SELECT command. This may be useful for single-purpose cards, where the main application resides in this implicitly selected DF.
Whether the card supports it, may be indicated in the Card capabilities in the historical bytes of the ATR, see ISO 7816-4.
In javacard context the corresponding mechanism is called implicitly selected application.