Research And Implementation Of TCP/IP Protocol Based On Smartcard Simulation System

The aim of the research on TCP/IP stack in a smart card is to implement the connection between smart cards and Internet, the key of which is to design appropriately embedded TCP/IP stack that is suitable for smart cards and the interconnection models between smart cards and Internet to make the smart card system connected to Internet both meet the requirements of network communication and save the memory space maximumly. The former research is the foundation on which smart cards obtain the accessing ability to networks, while the latter solves the problem how a smart card can connect to Internet. An Internet smart card just is a kind of smart cards that implemented a TCP/IP stack and have the ability to connect to Internet. As compared with traditional smart cards used in a network, the difference between them is that Internet smart cards implemented a TCP/IP stack and can communicate with any network node on Internet directly. At the same time, the accessing to smart cards was controlled by applications in smart cards. Moreover, Internet smart cards can be accessible in heterogeneous multiplatform environments since the thin client model was adopted. The traditional system structure of smart cards connected to Internet mainly consists of the smart card system and the cardreader terminal system which were separate from each other but both of which are subordinated to the host that is able to access to networks. Based on the traditional system structure of smart cards, the smart card system was separated from the host and appended a network interface device to obtain the accessing ability to networks. Furthermore, a smart card was integrated into a cardreader terminal as one single device connected to Internet with a network interface.According to the two application fields of remote access and security authentication, the Remote Control Model and the Proxy Model, which were the two interconnection models of smart cards connected to Internet and provided the theoretical support for the application of Internet smart cards, were advanced. Through detailed analysis of the working model and the process of data exchange between a smart card and a terminal, the mechanism of the two interconnection models were set forth. The Remote Control Model was realized in order to validate it actually. First of all, the network driver was designed. According to the characteristics of the hardware architecture and applications of smart cards, the embedded TCP/IP stack was devised through tailoring and optimizing the standard TCP/IP stack to satisfy the demand of applications of Internet smart cards under the condition of minimum resources consumption. On basis of the embedded TCP/IP stack, the calling interface of server-side programs, EGI that generated dynamic web pages and called server-side programs to execute such operation as reading and writing of smart cards with script programs, was defined.