MIFARE based smart cards are being used in an increasingly broad range of applications (including transport ticketing, access management, e-payment, road tolling, and loyalty applications). While all of these applications could be stored on one single card, at least for the short term, it is more likely that people will have several different MIFARE based smart cards in their wallets.

To maintain the speed and convenience of MIFARE's tap-and-go operation, the MIFARE Application Directory (MAD) defines common data structures for card application directory entries, allowing terminals to identify the right card (and the right memory sector within the card) without the need to perform a comprehensive search through all of the cards’ memories until the appropriate application is found.

Started in 1995, we have more than 600 registered applications worldwide benefiting from the MIFARE Application Directory today.

A typical example is when a person has MIFARE based smart cards for both access management to his office and public transport fare collection. With the MAD, when the cardholder wants to enter his office, the access management terminal identifies the two cards and is able to choose the correct one very quickly, simply by checking the MAD.

The MAD standard uses registered Application IDentifiers (AIDs) in sector 0x00 (and sector 0x10 if applicable) of the card’s memory to enable identification of all registered card applications. Terminal software can then take advantage of this feature using these sector pointers instead of physical sector addresses.

The technical documentation on MAD and a regularly updated list of registered applications can be found here.