Smart Card File System

By 2010/10/06Smart Cards

Some of the smart card file system tree as the DOS file system. ISO7816.4 provided by the smart card file is divided into: DF (Dedicated File) and EF (Elementary File). DF contains some control information, it can be EF or DF of the parent. This is some like the DOS files in the directory. EF is a unit of data collection, it can not be any files in the parent document. This is some like the DOS in the TXT file.

As smart cards using different security mechanisms, such security mechanism in the following two aspects: one for the microprocessor card than for read-only memory card is more complicated.
Read the information from the card to control aspects:
Limit the scope of smart card users
Some of the smart card, anyone can read the card information, names and blood type as the records of the patients medical cards, smart cards generally do not set this password, as long as anyone can get the card to read the card information. At this time the card body itself is a form of protection.
Cardholders can only read information for the smart card usually called PIN (personal identification number) to protect the password in the form of information on the card, usually by a 4-8 PIN numbers, card reader through the keyboard input, it allows the cardholder enter the password three times, and if none of the three lose, the card will be locked, only the PIN code on, the user can operate the card. At present there are also some more advanced form of the password being developed.
Can only read information for third-party smart card can be read only on the card issuer information. (For example, issuers can be rewritten only information on the e-wallet). At this time the smart card from the 16-32 digit password to protect.
Limited information on the smart card reader the way (read-only, you can add, modify or erase). Stored on the smart card information is generally divided into several parts:
Read-only information
The information can be added only
Updated information only
The information can not be read
This information can be stored in some of the password can not read the storage area.
The structure and support from the card encryption algorithm to control
As mentioned above only the right to know the password to use the talent to make smart cards, but if need be by radio or telephone lines in different places on the card information to send to must also have an additional means of protection.

Means of protection is encryption, which seems to send the information to be translated into foreign languages who can not read. Microprocessor smart cards with encryption and decryption (to read something and then translated back) of the features that make the transmission of information stored on the card, but also worry about leaks occur.

Through encryption, smart card information can be translated into hundreds of millions of “foreign language”, and need to communicate, you can randomly choose one. This prevention mechanism to ensure that the use of real and effective cards and computers, makes it almost impossible to send the information to steal halfway.This is the reason why Smart Card not as same as the formal Business Plastic Cards.