Guideline to select DESFire Application ID

[Ahlers]

Hello,

I would like to create an application on a DESFire media. For that I have to select an application ID (AID). According my understanding I'm not restricted in the value of that ID. It just has to be in the range 1 to 0xFFFFFF. But it's also not possible to have two applications with the same ID on one media.

As I want to allow also other operators to put their apps on the same media I have to somehow make somewhat (many somes) secure that both use different AIDs. Of course we have "the first wins".

So is there any guideline which value could be used? Or are some ranges somehow reserved for something?

BR
Erwin Ahlers

[Ahlers]

I found AN10787 "MIFARE Application Directory (MAD)". This contains a proposal for AID selection. It includes also the information that I should register new classic application IDs. 

But this claccis application ID is a 2 Byte value where the higher value is already fixed as function cluster. So I have only one byte left as application code. That's not much.

So is MAD really used in practice? I haven't seen it until now, but have just a very narrow use of DESFire media until now.

BR
Erwin Ahlers

[EduardoZamora]

Hello @Ahlers

Hope you are doing well.

MIFARE Application Directory (MAD) is a proposal; this may not be a mandatory process but it could be a good practice to register the AID so they are unique.

Regards,
Eduardo.