Communication system using communication network and communication method

Abstract

A communication system for guaranteeing only one each of two processing operations, correlated with each other and executed on different devices. A server has a unit which, on receipt of a first processing request, with identification information, executes this processing only once for one item of the identification, and a unit for transmitting a first processing completion notice to the transmission source of the processing request on completion of the first processing or on re-receipt of the processing request for the first processing with the same identification of the completed first processing. The client has a server, a unit for transmitting the processing request for first processing with identification information, a unit for executing a second processing, previously correlated with the first processing, on receipt of the completion notice, and a unit for re-transmitting a processing request on detection of an error before receipt of a transmitted completion notice.

1 . A client device for performing concerted processing with a server device connected thereto over a network, comprising: 
 processing request transmitting means for transmitting a processing request for first processing, afforded with the identification information, to said server device;    second processing executing means which, on receipt of a completion notice of said first processing from said server device, executes second processing, correlated in advance with said first processing; and    re-transmitting means which, if a communication error has been detected before receipt of said completion notice to said processing request transmitted by said processing request transmitting means, re-transmits said processing request to said server device.    
     
     
         2 . The client device as recited in  claim 1  further comprising processing completion reply transmitting means which, on completion of said second processing, transmits a processing completion reply for said second processing to said server device.  
     
     
         3 . The client device as recited in  claim 1  further comprising identification information request transmitting means for transmitting a request for identification information to said server device; 
 said processing request transmitting means conferring the identification information, transmitted from said server device responsive to said request for identification information, to said processing request for said first processing.    
     
     
         4 . The client device as recited in  claim 3  further comprising inspection means which, on receipt of the encrypted identification information, obtained on collectively encrypting the random numbers and the identification information, from said server device, decodes said encrypted identification information to take out said random numbers to check for matching between the random numbers thus taken out and the random numbers previously delivered to said server device.  
     
     
         5 . The client device as recited in  claim 1  wherein said processing request transmitting means collectively encrypts the processing request for said first processing, having said identification information conferred thereto, and random numbers, and transmits the encrypted processing request to said server device; there being further provided inspection means for inspecting matching between random numbers for inspection conferred to said completion notice sent from said server device and the random numbers collected to said processing request.  
     
     
         6 . A concerted processing method in a client device adapted for executing concerted processing with processing by a server device connected to the client device over a network, comprising the steps of 
 transmitting a processing request for said first processing, afforded with the identification information, to said server device; and    executing second processing, correlated in advance with said first processing, on receipt of a completion notice of said first processing from said server device, and re-transmitting said processing request to said server device if a communication error has been detected before receipt of said completion notice.    
     
     
         7 . A content validating method in a client device adapted for performing the processing of validating invalidated contents, in a concerted operation with the processing by a server device, comprising the steps of: 
 transmitting a processing request for billing processing, afforded with the identification information, to said server device, validating the invalidated contents on receipt of the completion notice of said billing processing from said server device, and re-transmitting said processing request to said server device on detection of a communication error before receipt of said completion notice.