Security features in on-line and off-line delivery of applications

Abstract

A system and method for protecting against unauthorized use of an application on a computer system. First, saved data associated with the application is stored. Storing the save data includes binding usage information to the saved data, wherein the usage information includes one or more parameters set by the application indicating how the application has been used by a user. Then, a request to access the saved data is processed. Processing the request includes performing an integrity check on the bound usage information and saved data, and denying access to the saved data if the integrity check determines that the usage information has been altered by a user.

1 . A method for protecting against unauthorized use of an application on a computer system, comprising: 
 (a) storing saved data associated with the application, wherein storing the saved data comprises binding usage information to the saved data, wherein the usage information includes one or more parameters set by the application indicating how the application has been used by a user; and    (b) processing a request to access the saved data, wherein processing the request comprises 
 (i) performing an integrity check on the bound usage information and saved data, and  
 (ii) denying access to the saved data if the integrity check determines that the usage information has been altered by a user.  
   
   
   
       2 . The method of  claim 1 , wherein the saved data comprises data saved by a user while running the application.  
   
   
       3 . The method of  claim 1 , wherein storing the saved data further comprises storing the bound usage information and saved data in a repository.  
   
   
       4 . The method of  claim 1 , wherein steps (a) and (b) each further comprise intercepting a file input/output (I/O) request generated as a result of execution of the application.  
   
   
       5 . The method of  claim 4 , wherein intercepting a file I/O request comprises intercepting a file I/O request by a set of file system hooks.  
   
   
       6 . The method of  claim 1 , wherein binding usage information to the saved data comprises: 
 applying a predefined integrity function to the usage information and the saved data to generate a result; and    storing the result.    
   
   
       7 . The method of  claim 6 , wherein performing an integrity check on the bound usage information and saved data comprises: 
 applying the predefined integrity function to the usage information and the saved data to generate a new result; and    comparing the new result to the previously-stored result.    
   
   
       8 . The method of  claim 7 , wherein the new result and the previously-stored result each comprise a checkword.  
   
   
       9 . The method of  claim 8 , wherein each checkword comprises a cyclic redundancy code.  
   
   
       10 . The method of  claim 1 , further comprising: 
 executing the application in an offline mode.    
   
   
       11 . The method of  claim 1 , wherein the usage information includes at least one of a parameter that indicates a number of times an application has been executed and/or a parameter that indicates an amount of time that an application has been in use.  
   
   
       12 . The method of  claim 1 , wherein the saved data comprises at least one of saved game information or a saved document.  
   
   
       13 . The method of  claim 1 , further comprising: 
 denying access to the application and/or saved data if the usage information indicates that a usage limit has been exceeded.    
   
   
       14 . A computer system that provides protection against unauthorized use of an application, comprising: 
 means for storing saved data associated with an application, wherein the means for storing the saved data comprises means for binding usage information to the saved data, wherein the usage information includes one or more parameters set by the application indicating how the application has been used by a user; and    means for processing a request to access the saved data, wherein the means for processing the request comprises means for performing an integrity check on the bound usage information and saved data, and means for denying access to the saved data if the integrity check determines that the usage information has been altered by a user.    
   
   
       15 . The computer system of  claim 14 , wherein the saved data comprises data saved by a user while running the application.  
   
   
       16 . The computer system of  claim 14 , wherein the means for storing the saved data further comprises means for storing the bound usage information and saved data in a repository.  
   
   
       17 . The computer system of  claim 14 , further comprising means for intercepting a file input/output (I/O) request generated as a result of execution of the application and for redirecting the file I/O request to the means for storing saved data or the means for processing a request to access the saved data.  
   
   
       18 . The computer system of  claim 17 , wherein the means for intercepting a file I/O request comprises a file system hook.  
   
   
       19 . The computer system of  claim 14 , wherein the means for binding usage information to the saved data comprises means for applying a predefined integrity function to the usage information and the saved data to generate a result, and means for storing the result.  
   
   
       20 . The computer system of  claim 19 , wherein the means for performing an integrity check on the bound usage information and saved data comprises means for applying the predefined integrity function to the usage information and the saved data to generate a new result and means for comparing the new result to the previously-stored result.  
   
   
       21 . The computer system of  claim 20 , wherein the new result and the previously-stored result each comprise a checkword.  
   
   
       22 . The computer system of  claim 21 , wherein each checkword comprises a cyclic redundancy code.  
   
   
       23 . The computer system of  claim 14 , further comprising: 
 means for executing the application in an offline mode.    
   
   
       24 . The computer system of  claim 14 , wherein the usage information includes at least one of a parameter that indicates a number of times an application has been executed or a parameter that indicates an amount of time that an application has been in use.  
   
   
       25 . The computer system of  claim 14 , wherein the saved data comprises at least one of saved game information or a saved document.  
   
   
       26 . The computer system of  claim 14 , further comprising means for denying access to the application and/or saved data if the usage information indicates that a usage limit has been exceeded.  
   
   
       27 . A method for protecting against unauthorized use of an application on a computer system, comprising: 
 (a) storing saved data associated with the application, wherein storing the saved data comprises 
 (i) generating a checkword based on usage information associated with the application, wherein the usage information includes one or more parameters set by the application indicating how the application has been used by a user, and  
 (ii) encrypting the saved data based on the checkword; and  
   (b) accessing the saved data from the repository, wherein accessing the saved data comprises 
 (i) generating a new checkword based on the usage information, and  
 (ii) decrypting the saved data based on the new checkword.  
   
   
   
       28 . The method of  claim 27 , wherein the saved data comprises data saved by a user while running the application.  
   
   
       29 . The method of  claim 27 , wherein storing the saved data further comprises storing the saved data in a repository.  
   
   
       30 . The method of  claim 27 , wherein steps (a) and (b) each further comprise intercepting a file input/output (I/O) request generated as a result of execution of the application.  
   
   
       31 . The method of  claim 30 , wherein intercepting a file I/O request comprises intercepting a file I/O request by a set of file system hooks.  
   
   
       32 . The method of  claim 27 , wherein generating a checkword comprises generating a cyclic redundancy code.  
   
   
       33 . The method of  claim 27 , further comprising: 
 executing the application in an offline mode.    
   
   
       34 . The method of  claim 27 , wherein the usage information includes at least one of a parameter that indicates a number of times an application has been executed or a parameter that indicates an amount of time that an application has been in use.  
   
   
       35 . The method of  claim 27 , wherein the saved data comprises at least one of saved game information or a saved document.  
   
   
       36 . The method of  claim 27 , further comprising: 
 denying access to the application and/or saved data if the usage information indicates that a usage limit has been exceeded.    
   
   
       37 . A computer system that protects against unauthorized use of an application, comprising: 
 means for storing saved data associated with the application, wherein the means for storing the saved data comprises means for generating a checkword based on usage information associated with the application, wherein the usage information includes one or more parameters set by the application indicating how the application has been used by a user, and means for encrypting the saved data based on the checkword; and    means for accessing the saved data, wherein the means for accessing the saved data comprises means for generating a new checkword based on the usage information, and means for decrypting the saved data based on the new checkword.    
   
   
       38 . The computer system of  claim 37 , wherein the saved data comprises data saved by a user while running the application.  
   
   
       39 . The computer system of  claim 37 , wherein the means for storing the saved data further comprises means for storing the saved data in a repository.  
   
   
       40 . The computer system of  claim 37 , further comprising means for intercepting a file input/output (I/O) request generated as a result of execution of the application and for redirecting the file I/O request to the means for storing saved data or the means for accessing the saved data.  
   
   
       41 . The computer system of  claim 40 , wherein the means for intercepting a file I/O request comprises a file system hook.  
   
   
       42 . The computer system of  claim 37 , wherein the means for generating a checkword comprises means for generating a cyclic redundancy code.  
   
   
       43 . The computer system of  claim 37 , further comprising: 
 means for executing the application in an offline mode.    
   
   
       44 . The computer system of  claim 37 , wherein the usage information includes at least one of a parameter that indicates a number of times an application has been executed or a parameter that indicates an amount of time that an application has been in use.  
   
   
       45 . The computer system of  claim 37 , wherein the saved data comprises at least one of saved game information or a saved document.  
   
   
       46 . The computer system of  claim 37 , further comprising means for denying access to the application and/or saved data if the usage information indicates that a usage limit has been exceeded.