Content delivery apparatus, user terminal device, relief management method and computer program

Abstract

A content delivery apparatus, when a content delivery request is outputted from a user terminal device, encrypts the requested content with an encryption key, adds a view period to it to deliver it to a request source and delivers a viewing key in response to a view request from the user terminal device within the view period. A user relief management unit monitors failure information notifying, grasps a delivery disabled period from the failure information, specifies a delivery destination user for a content of which the view period is overlapped with the delivery disabled period and issues a relief right with a relief period specified thereto to the specified user. A contract period processing unit manages the relief right and permits viewing within the relief period set by the relief right when a view right based on the relief right is output from the user terminal device.

1 . A content delivery apparatus, when a content delivery is requested from a user terminal device via a network, encrypting a requested content, delivering it to a request source while managing a view period, and delivering view permission information to decrypt the encrypted content in response to a view request from the user terminal device, comprising: 
 an unit to manage a delivery disabled period in which a delivery of the view permission information becomes impossible;    an unit to specify a delivery destination user, for a content of which the view period is overlapped with the delivery disabled period, as a user to be relieved;    an unit to issue a relief right with a relief period specified thereto to the user to be relieved to notify issue to the corresponding user terminal device; and    an unit to manage the relief right to deliver the view permission information only within the relief period set to the relief right when the view request is output from the user terminal device on the basis of the relief right.    
     
     
         2 . The content delivery apparatus according to  claim 1 , wherein the unit to manage relief right starts the relief period based on the relief right from a time of the first view request after expiring the view period and also after a relief exertion.  
     
     
         3 . The content delivery apparatus according to  claim 1 , wherein the unit to manage relief right ignores the view request based on the relief right within the view period.  
     
     
         4 . A user terminal device used for a content delivery system, outputting a delivery request for a content to a content delivery apparatus via a network in response to an operation of a user, storing a content encrypted and delivered with a view period by and from the delivery apparatus in response to the delivery request and decrypting the stored content by receiving view permission information to decrypt the encrypted content which is delivered from the content delivery apparatus in response to a view request within the view period, and when the content delivery apparatus manages a delivery disabled period in which a delivery of the view permission information becomes impossible, specifies a delivery destination user for a content of which the view period is overlapped with the delivery disabled period, as a user to be relieved, issues a relief right with a relief period specified thereto to the user and notifies issue of the relief right to the corresponding user terminal device, comprising: 
 an unit to present a notification of the issue of the relief right; and    an unit to exert the relief right a view request based on the relief right to the content delivery apparatus in accordance with an input instruction from the user.    
     
     
         5 . A relief management method of a content delivery system used for a system, when a content delivery is requested from a user terminal device via a network, encrypting a requested content, delivering it to a request source while managing a view period, and delivering view permission information to decrypt the encrypted content in response to a view request within the view period from the user terminal device, comprising: 
 managing a delivery disabled period in which a delivery of the view permission information becomes impossible;    specifying a delivery destination user for a content of which the view period is overlapped with the delivery disabled period, as a user to be relieved;    issuing a relief right with a relief period specified thereto to the user to be relieved to notify issue to the corresponding user terminal device; and    managing the relief right to deliver the view permission information only within the relief period set to the relief right when a view request is output from the user terminal device on the basis of the relief right.    
     
     
         6 . The relief management method of the content delivery system according to  claim 5 , further comprising: 
 starting the relief period based on the relief right after expiring the view period and also at a time of the first view request after a relief exertion.    
     
     
         7 . The relief management method of the content delivery system according to  claim 5 , further comprising: 
 ignoring a view request based on the relief right within the view period.    
     
     
         8 . A computer program recorded on a recording medium for a content delivery apparatus which is used for the content delivery apparatus and when a content delivery is requested from a user terminal device via a network, makes a computer execute processing of encrypting a requested content, delivering it to a request source while managing a view period, and delivering view permission information to decrypt the encrypted content in response to a view request from the user terminal device, the program comprising: 
 means for instructing the computer to manage a delivery disabled period in which a delivery of the view permission information becomes impossible;    means for instructing the computer to specify a delivery destination user for a content of which the view period is overlapped with the delivery disabled period, as a user to be relieved;    means for instructing the computer to issue a relief right with a relief period specified thereto to the user to be relieved and notify issue to the corresponding user terminal device; and    means for instructing the computer to manage the relief right to deliver the view permission information only within the relief period set to the relief right when a view request is output from the user terminal device on the basis of the relief right.    
     
     
         9 . The computer program according to  claim 8 , further comprising: 
 means for instructing the computer to start the relief period based on the relief right after expiring the view period and also at a time of the first view request after a relief exertion.    
     
     
         10 . The computer program according to  claim 8 , further comprising: 
 means for instructing the computer to ignore a view request based on the relief right within the view period.