Usb Protocol For Multi-application Smart Card Research

The software structure and integrated circuit of the Smart Card has remained its basic design method and internal architecture since it was invented. On the one hand, the technology of IC card has gained great success in business area; On the other hand, it was challenged by other new technology. Traditional SIM card's capacity was only between 16K bytes to 128K bytes, and it CPU was limited in 8 bit. The operation in traditional SIM card was restricted by its storage and processing capability. At present, a mass of math computation and data transmission was needed in new mobile increment operation, such as mobile TV, mobile electronic transaction, multimedia application, and so on. All this make a great challenge to traditional SIM card development.Super Smart Card(SSC: Smart Storage Chip) was a kind of multi application Smart Card aimed at this needs which integrates SIM, USB Mass Storage and SD/MMC storage and so on. The particular 3in1 feature has greatly expanded the SIM operation extension. Moreover, it combines the high-speed interface(USB, SD/MMC) and low-speed interface(ISO 7816) in one Real Time Operating System(RTOS) by using different task. Thus the SSC card was used more and more widely in IC area.Along with the development of SSC, the transmission bottle-neck by using ISO7816 protocol for transmission and issuing cards becomes more and more significant. This transformation speed in Kbytes meets far from the new operation's acquirement. The speed of card issuing in Mbytes data transformation was restricted by this. Thus, How to transmitting SIM data with high-speed interface(USB) is the critical section in problem solving.This paper implements USB protocol extension to transfer hidden SIM customer related data in PC and SSC card. By this method, not only the Mass Storage data like enterprise phonebook, electronic book could be developed, but secure access control could also be implemented in the SSC card. It ensures security in data transmission. At the same time, USB Card issuing could enhance the issuing speed with its high-speed interface.Finally, this paper brings a method of USB protocol extension. With this method, the critical data could be transferred safely between PC and SSC card.