| 摘要 |
A networked computer system comprises a network that includes a server, and at least one client authorised for communication with that server, at which client data may be input into the system. Each such client has a memory storing a table containing a plurality of code words. The client is also provided with an encryption engine adapted to encrypt the input data using code words from the table to provide packets of data to be transmitted via the network to the server. Each packet is encrypted using a code word selected for that packet or for a train of such packets from the table. The server includes a decryption engine adapted to decrypt data packages received by the server for processing by the server. A table of code words is stored at the server, the table including all code words associated with all clients authorised for communication with the server. The decryption engine identifies from each data package received by the server whether the particular package was encoded using a code word present in the table and, if so, decrypts the package using the particular code word. Each client preferably comprises a data input station having a station code associated therewith, and each said user of the system has a user code required for logging into the system. Each client encryption engine is then arranged to combine and encrypt the station code and the user code when a user logs into the system at a particular station to provide an encrypted log-on signal. The data input station transmits the encrypted log-on signal to the server. The decryption engine of the server is linked to an access controller, and includes a memory storing a table of permitted combinations of station code and user code. The decryption engine decrypts received encoded log-on signals and configures the access controller to allow access from a particular data input station to, and manipulation of data in, the data processor only when the decrypted log-on signal corresponds to a permitted such combination. |
