Making applications?


#1

I’ve been trying to find documentation on how to program and make applications for the DESfire EV1.
I’ve looked at the data sheet but, I’m not seeing anything that points me in the right direction. I’m a n00b when it comes to smart card applications and have no experience.


#2

Basically the DESFire EV1 has “applications” that are really nothing more than special “file types”. The DESFire EV1 has 8k of space that can be allocated into multiple “files”. The chip cannot actually run applications or software, but each file type has some special processing features associated. For example, there is an “electronic purse” or stored-value file type that allows special “increment / decrement” features that allows one key to “add value” to a purse without being able to get balance or decrement value, and another key can be used to decrement and get balance, which is a great way to segregate roles for a chip that moves between multiple entities which may or may not want to share the same keys for performing thes functions.

In essence, each file defined on the chip will get an AID (application identifier). These can be anything you want, but there are some specially defined AIDs. For example, the NFC Type 4 NDEF AID is D2 76 00 00 85 01 01 as described in section C.1 in this NFC Type 4 tag comm flow PDF

NFCForum-TS-Type-4-Tag_2.0.pdf (511.0 KB)

I hope that clarifies things a bit.


#3

Thank you for the documentation! I will read into it. I have a CS back group and I’m really interesting in what is possible/the limitations.


#4

I think you might be really interested in the VivoKey Flex One from VivoKey Technologies (my other company)… it will run full java card applets in vivo.