Smart card is the core of Smart card technology, and its performance and cost play an important role in the promotion and use of Smart card technology. in order to improve the standardization and universality of Smart cards, the international Organization for Standardization has specified the interfaces and communication protocols of Smart cards in detail.

the first type: non-confidential memory card; its embedded chip is equivalent to ordinary serial E2PROM memory, and some chips also add the function of writing protection in specific areas. It is convenient for information storage, simple to use and inexpensive, and can replace magnetic cards on many occasions, but because it has no information confidentiality function of its own, it can only be used for applications with low confidentiality requirements.

the second category: encrypted memory card; encrypted memory card embedded chip increases the control logic outside the storage area. Before accessing the storage area, the password needs to be checked. Only when the password is correct, the access operation can be performed. This information has good confidentiality and is similar to a normal memory card.

the third type: CPU card; CPU card embedded chip is equivalent to a special type of microcontroller. Because of its large storage capacity, strong processing capability, and secure information storage, the CPU card has an algorithm unit and operating system in addition to the controller, memory, and time control logic. therefore, it is widely used in applications with particularly high information security requirements.

the fourth type:Super Smart card; there are MPU and memory on the card, as well as a health disk, LCD display and power supply, and some cards have fingerprint identification devices.