Computation process between IC card and terminal - provides computation check without direct transmission between units to protect access to coding data to prevent unauthorised access

摘要

The IC chip card has a built in CPU (1) that connects with an internal bus having a RAM (3) memory, a ROM programme memory (4) and a data memory (5). In addition there is a timer circuit (12) and input/output circuit (7). The data memory (5) is divided into a number of regions. In one region (5-a) a pseudo random number generator algorithm is stored, in another (5-b) a security code. Other regions store generated random numbers (5-c), coding algorithms (5-d), computation codes (5-e) and user programme data (5-f). The card is used with a terminal (27) having a memory (24) storing data that relates to that in the card memory. ADVANTAGE - Protects against misuse.