Design And Implementation Of Part Of The Mondnles In Beijing One-card Online System

Since the opening of the municipal transportation card system in May 2006, it has been running for 4 years, extending from the areas of subway, bus and taxi to parks, supermarkets, convenience stores, restaurants, cinemas and pharmacies and other aspects of city life, bringing great convinience, the volume of transaction has increased sharply. The expansion of consumption has brought about rapid development of the one-card transaction, meanwhile a higher ecurity of the card and recharge transaction is needed.The method of current transaction handling is offline, transactions are processed directly in the terminal, there will be special data collecting devices to collect data from the terminal at intervals, sending it to the settlement center, then the settlement center will process the account associated with the card. Thus, there will be drawback in data consistency and data security. This article will add an extra online system parallel to the offline system to process the transactions of recharge, consumption and returning card. To terminals in the online system network, before processing a transaction, they will need to send an application message to the online system. The system need to verify information, like terminal, when the check has been passed, a response will be sent to the terminal, then the terminal can continue the transaction, the system will record transaction data to the settlement center at intervals, to update account information associated.This article explain the architecture of one-card online system as well as specific business processes, key system, the encryption and decryption processing of transaction message and related techniques used in the system such as Unix Socket, message queues, etc.