Authorization using ciphertext tokens

Abstract

According to the invention, a method for securing a plaintext object within a content receiver is disclosed. In one step, a secure portion of a secure object and a plaintext remainder of the secure object are received. Which portion of the secure object is the secure portion is determined. The secure portion is decrypted to provide a plaintext portion. The plaintext object that comprises the plaintext portion and the plaintext remainder is formed. The plaintext object is stored.

What is claimed is:  
     
         1 . A method for securing a plaintext object within a content receiver, the method comprising steps of: 
 receiving a secure portion of a secure object;    receiving a plaintext remainder of the secure object;    determining which portion of the secure object is the secure portion;    decrypting the secure portion to provide a plaintext portion;    forming the plaintext object that comprises the plaintext portion and the plaintext remainder; and    storing the plaintext object.    
     
     
         2 . The method for securing the plaintext object within the content receiver as recited in  claim 1 , further comprising steps of: 
 selecting a secure portion of the plaintext object to encrypt;    encrypting the secure portion;    sending the secure portion and a plaintext remainder to a content receiver; and    providing a key that is used in decryption of the secure portion.    
     
     
         3 . The method for securing the plaintext object within the content receiver as recited in  claim 1 , further comprising a step of reporting purchase of the plaintext object a point away from the content receiver.  
     
     
         4 . The method for securing the plaintext object within the content receiver as recited in  claim 3 , wherein the second listed receiving step is performed before the reporting step.  
     
     
         5 . The method for securing the plaintext object within the content receiver as recited in  claim 1 , wherein the decrypting step comprises a step of decrypting the secure portion with an access control processor.  
     
     
         6 . The method for securing the plaintext object within the content receiver as recited in  claim 1 , wherein the secure portion is less than one-half the size of the secure object.  
     
     
         7 . A method for securing a plaintext object within a conditional access system, the method comprising steps of: 
 selecting a secure portion of the plaintext object to encrypt;    encrypting the secure portion;    sending the secure portion of the plaintext object to a content receiver;    sending a plaintext remainder of the plaintext object to the content receiver; and    providing a key to the content receiver wherein the key is used in decryption of the secure portion.    
     
     
         8 . The method for securing the plaintext object within the conditional access system as recited in  claim 7 , further comprising steps of: 
 receiving the secure portion of a secure object;    receiving the plaintext remainder of the secure object;    determining which portion of the secure object is the secure portion;    decrypting the secure portion to provide a plaintext portion;    forming the plaintext object that comprises the plaintext portion and the plaintext remainder; and    storing the plaintext object.    
     
     
         9 . The method for securing the plaintext object within the conditional access system as recited in  claim 7 , further comprising a step of reporting purchase of the plaintext object a point away from the content receiver.  
     
     
         10 . The method for securing the plaintext object within the conditional access system as recited in  claim 9 , wherein the reporting step is performed before the second listed sending step.  
     
     
         11 . The method for securing the plaintext object within the conditional access system as recited in  claim 7 , further comprising a step of determining the secure portion wherein removal of the secure portion from the plaintext object renders the plaintext object inoperable.  
     
     
         12 . The method for securing the plaintext object within the conditional access system as recited in  claim 7 , further comprising a step of changing authorization of the content receiver from a point remote to the content receiver.  
     
     
         13 . The method for securing the plaintext object within the conditional access system as recited in  claim 7 , further comprising a step of receiving purchase information from the content receiver at a location remote to the content receiver.  
     
     
         14 . The method for securing the plaintext object within the conditional access system as recited in  claim 7 , wherein the key is a symmetric key.  
     
     
         15 . A method for securing an object within a content receiver, the method comprising steps of: 
 receiving a first portion of the object;    recognizing a purchase request from a user of the content receiver for the object;    reporting the purchase request to a point away from the content receiver;    receiving a second portion of the object after the reporting step; and    storing the object in the content receiver.    
     
     
         16 . The method for securing the object within the content receiver as recited in  claim 15 , wherein the second portion is received in encrypted form.  
     
     
         17 . The method for securing the object within the content receiver as recited in  claim 15 , wherein the first portion is greater than nine hundred percent larger than the second portion.  
     
     
         18 . The method for securing the object within the content receiver as recited in  claim 15 , further comprising the step of reformulating the object from the first and second portions.  
     
     
         19 . The method for securing the object within the content receiver as recited in  claim 15 , wherein the second listed receiving step comprises a step of receiving the second portion by way of a secured distribution channel.