Views: 0 Author: Site Editor Publish Time: 2022-06-22 Origin: Site
Smart card classification:
Smart card is the core of smart card technology. 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 card, the international standardization organization has made detailed regulations on the interface and communication protocol of smart card. The manufacturers of smart card include Siemens, ATMEL, Gemplus, Motorola, microchip, etc.
The smart card belongs to the semiconductor card. Semiconductor card uses microelectronic technology to store and process information. According to its structure, the smart card can be divided into general memory card, encrypted memory card, CPU card and super smart card
Unencrypted memory card
The embedded chip is equivalent to the ordinary serial E2PROM memory. Some chips also add write protection function in specific areas. This kind of card has the advantages of convenient information storage, simple use, low price, and can replace magnetic card in many occasions. However, because it does not have the function of information security, it can only be used in applications with low security requirements.
The embedded chip of the encryption memory card adds control logic outside the memory area. Before accessing the memory area, you need to check the password. Only when the password is correct, you can access the information. This kind of information has good confidentiality and is similar to the ordinary memory card.
CPU card (smart card)
The embedded chip of CPU card is equivalent to a special type of single-chip microcomputer. In addition to controller, memory, timing control logic, algorithm unit and operating system, the CPU card has the characteristics of large storage capacity, strong processing capacity, information storage security and so on. Therefore, it is widely used in the situation of high information security requirements.
Super smart card
The card has MPU and memory, key disk, LCD and power supply, and some cards also have fingerprint identification device.
According to the data reading and writing mode, smart cards can be divided into contact IC card and non-contact IC card
Contact IC card
The former is read and write by the contact of the reading and writing equipment and the contact on the card; the international standard ISO7816 series specifies this kind of IC card.
Contactless IC card
he latter has no circuit contact with the reading and writing equipment and is read and written by non-contact reading and writing technology (such as optical or radio technology). In addition to the memory unit, the embedded chip. Besides the control logic, the RF transceiver circuit is added. This kind of card is generally used in the occasion of frequent access and high reliability requirements. The international standard iso10536 series describes the relevant regulations of contactless IC card.
According to the classification of data exchange format, smart cards can be divided into serial and parallel:
Serial IC card
When the smart card exchanges data with the outside world, the data stream is input and output in serial mode. At present, most of the IC cards in the application belong to the serial IC card class. The serial IC card interface is simple and easy to use. The international organization for standardization has specially developed relevant standards for it.
Parallel IC card
In contrast to the serial IC card, the data exchange of the parallel IC card is carried out in a parallel way, which can bring two benefits: first, the speed of data exchange is improved; second, the storage capacity can be significantly increased under the existing technical conditions. The manufacturers have made further exploration and put some products into use. However, due to the lack of corresponding international standards, there are still some problems in large-scale application.
In addition, relevant manufacturers have designed and manufactured various smart cards suitable for practical use, such as:
After the prepaid card leaves the factory, its characteristics before initialization are similar to that of the encrypted memory card, but its capacity is small. Once it is initialized by the user, its information reading is similar to that of the ordinary memory card. Its embedded chip is equivalent to a counter, but the counter can only be used for subtraction, not for addition. When the count is zero, the chip will be invalid. Therefore, it is one-time. This card is specially designed for prepaid use.
There are also many forms of hybrid cards, which make IC chips and magnetic cards on one card, and integrate contact type and non-contact type. They are generally called "hybrid cards".
In addition, the concept of optical card was put forward by an American company in 1981, which enriched the card data storage mode. Optical card is composed of semiconductor laser materials, which can store and record a lot of information. There are two kinds of optical card recording formats: Canon and delta. Both forms have been accepted as international standards by the international organization for standardization. Optical card has the advantages of small size, easy to carry, safe and reliable data, large capacity, strong anti-interference, not easy to change, good confidentiality and relatively low price.
Some smart cards have been provided as standard products, which will be described in detail in later chapters. Some need to be customized. This book is only a programmatic introduction. In addition, some companies are planning to use flash memory technology to manufacture smart cards to further expand capacity, improve speed, reduce cost and power consumption, which will be another leap forward of smart card technology. It is predicted that with the continuous development and progress of new technologies and processes, new card types will continue to appear in the future.