Design And Implementation Of An Electricity Prepayment System

IC card prepayment, a technical application area developed in the recent years , is used to solve the difficulty in collecting the fee of the public services, such as water, electricity, gas. This technique has been promoted gradually in the past few years. Data security is the most important technique problem of all the IC card prepayment product systems, but the majority of the IC card prepayment product systems on the current market haven't solved the data security problem perfectly. In this paper several topics are investigated: the password security of the IC card, encrypting and checking the data on the IC card, the security of the database, and a novel comprehensive data security design scheme is proposed, so that damages by passive and active attacks can been avoided. Reference to correlative products abroad and home, this paper puts forward with a kind of a new scheme of electric energy selling system which comes from the practical project.The paper can be divided into two parts: the former part introduces the design and realization of the system software based on relative database SQL Sever 2000 for selling electricity by IC card. The object-oriented develop tool Visual Basic 6.0 is adopted in software system design. Users can buy the electricity with the IC card and query the remainder. The windows interface is shown in software using ActiveX Data Object to realize serial communication. Friendly user interface, fresh menu window and strong control function are also provided to user. The later part generally describes the design of portable IC card electricity prepayment system,which includes the design of the function, hardware, software and data encryption technology.The paper mainly dissertates with the software of the system-IC card prepayment management system, after briefly introducing the whole IC card prepayment products system, and detailed introduces the character, selection and encryption of IC card and implements read-write and encryption of IC card, and the encryption arithmetic principle of the DES. In a word, by the means of the structural system analysis, the design and realization of the whole software is completed successfully.