IC card knowledge

IC card overview and Classification
1. IC card Definition
IC card is short for Integrated Circuit Card (Integrated Circuit Card), is a plastic card embedded with integrated circuit chip, its shape and size comply with international standards (ISO ). Generally, the chip uses non-volatile memory (ROM, EEPROM), protection logic circuit, and even CPU with microprocessor. An IC card with a CPU is a real smart card.
2. IC card classification
IC cards can be roughly divided:

Non-encrypted memory card: the card's Integrated Circuit Chip is mainly EEPROM, with data storage function, not data processing function and hardware encryption function.
Logical encrypted memory card: an encrypted logical circuit is added to the non-encrypted memory card. The encrypted Logical Circuit verifies the password to protect the data in the card from external access, however, it is only a low-level security protection and cannot prevent malicious attacks.
CPU card: Also known as a smart card. The integrated circuit in the card contains a microprocessor CPU and a storage unit [including random memory Ram, program memory Rom (flash), and user data memory (EEPROM) and Chip Operating System COS]. A cpu card with cos is equivalent to a microcomputer. It not only provides data storage functions, but also provides command processing and data security protection functions.
IC Card international standards
1. ISO 7816-1: 1987 Identification Card Integrated Circuit Card with contacts Part 1: Physical Properties
Specifies the physical characteristics of the card, including the size (same as ISO 7810 ).
2. ISO 7816-2: 1987 Identification Card Integrated Circuit Card with contacts Part 1: contact size and position
The size, position, and function of each contact are specified. Each contact should have a rectangular surface area of no less than 7mm mmx1. each contact is isolated from each other, but the shape and maximum size of the contact are not specified, therefore, IC card modules have various surface shapes, but the valid contact area and position of each contact are fixed. The IC card has 8 contacts. Currently, 6 contacts are generally used, and the other 2 contacts are reserved for future use.
3. ISO 7816-3: 1987 Identification Card Integrated Circuit Card with contacts Part 1: electrical signals and transmission protocols
It specifies the power supply and signal structure, as well as information exchange and communication protocols between the IC card and reader. The CPU card reader is developed based on this standard.
4. ISO 7816-4: 1987 Identification Card Integrated Circuit Card with contacts Part 1: inter-industry exchange commands
The commands and response information transmitted between the reader and the card, files in the card, data structures, and access methods are specified. The operating system cos of the CPU card reader and CPU card is developed according to this standard.
5. ISO 7816-5: 1987 Identification Card Integrated Circuit Card with contacts Part 1: Application Identifier (AID) Numbering System and registration process
The Application Identifier (AID) is mainly used in the CPU card to determine the address of the application in the card. It can include the ID of the registered application provider. Only SLE4442 and sle4428 cards in the logical Encryption Card have aid, which is globally unique and can increase application security.