There are numerous smart card systems, from payment systems to security and entry systems. Consequently, there are also different types of smart cards, and these include the contact cards, the contactless cards, the multi component cards and the dual interface cards. The difference in these lies in:

– The method of reading and writing of the card data.

– The chip type that is found in the card.

However, smart card systems all work based on the basic principal of how the smart card works. The smart card is physically identical to the credit/debit card, but internally different because it contains a microprocessor that is embedded in it. A credit card has a magnetic stripe. The scientific working of a smart card is a very detailed process that cannot be exhausted in a few pages. This article will therefore examine what is entailed in perhaps the main principle behind that, which is reading and writing of data.

Readers

The reader is that part in the smart card microprocessor that interfaces with the computer program for a large percentage of the processing of the card. There are basically two types of readers, the contact and the contactless readers. As the name suggests, the former depends on a physical link with card (and are very common), while the latter doesn’t.

The communications of card-to-reader in the contact readers is usually ISO 7816 T=0. Its maximum PTS speed is 115 kb (kilo baud). This makes it have a more secure and faster communication. On the other hand, the contactless reader communicates using a radio frequency and thus the card has to be in close range with the reader. This makes the readers more suitable in payment, transportation and Physical access control systems.

The Interface

The interface is the method through which the contact reader links with the PC and these include:

– USB ports,

– floppy disk slots,

– RS232 serial ports

– PCMCIA slots,

– Keyboard slots

– Infrared IRDA ports and

– Parallel port

The interface therefore forms the primary criterion for categorizing the various readers. There are readers that support many card types- both contact and contactless cards.

Terminals

These are specific to the system, and as such the security system terminal will be different from the POS system terminal and so on. They can be viewed as PCs that are self-contained with an operating system inside. Terminal connectivity is normally through GSM or TCP-IP network, and they use the normal OS’s.

Card Communication Between the Reader and the Terminal

The Application Protocol Data Units (APDUs) set the standard commands for CPU card communications. In simple terms, the APDUs facilitate the sending of user commands from the application system (APIs) to a reader. The user’s request is implemented by the communication between the reader and the smart card.

Looking at it technically, the determining factor in the communication is the chosen APIs. These APIs facilitate the effective communication of manufacturers’ readers and smart cards. But on the other hand, the terminal SDKs have their specific APIs for the given platform.

Edward Kendricks writes for CTS (www.cts-networks.co.uk), UK access control installation specialists.

Edward Kendricks writes for CTS (http://www.cts-networks.co.uk), UK access control installation specialists.

Author Bio: Edward Kendricks writes for CTS (www.cts-networks.co.uk), UK access control installation specialists.

Category: Computers and Technology
Keywords: security, automation, home, crime, business, door entry, smart card, contact card