Introduction to CPU Card Knowledge Tutorial - Chapter 3: What is Multi Application?

For CPU cards, people often pay attention to the multi application of CPU cards, which means that a CPU card can have multiple applications,

What is the security isolation of multiple applications?

We can imagine the card as a county government office building, for example:

First floor: Belongs to the civil affairs department

Second floor: Belongs to the education department

Third floor: belonging to the transportation department

Each department operates independently and does not interfere with each other, and they have no subordinate relationship in administration. Thus achieving the coexistence of multiple applications.

The civil affairs department intelligently handles the affairs of the civil affairs department, while the education department can only handle the affairs of the education department. Thus achieving secure isolation among multiple applications.

1、 Multiple applications coexist on one card

How is it achieved to have multiple applications coexisting on the card?

By creating multiple ADFs (i.e. creating multiple directories).

Each ADF represents an application. There are corresponding files under each ADF, corresponding

Store the corresponding data in the file.

2、 Security isolation between multiple applications

How is the security isolation between multiple applications achieved?

Realize through the internal security mechanism of the card.