Data protection system and game machine

Abstract

A data protection system is disclosed which is installed in a game machine together with a rewritable storage device, and protects the data stored in the storage device from illegal changes. A command receiving unit receives from the outside a command requesting data processing for the storage device. The received command is checked by a judgment unit against each valid command stored in a command storage unit. When the received command matches one of the valid commands, a data processing unit instructs the storage device to perform the data processing requested by the received command. When the received command does not match any of the valid commands, the data processing unit does not instruct the storage device to perform the data processing requested by the received command.

1 . A data protection system which is installed in a game machine together with a rewritable storage device and which protects the data stored in said storage device from illegal changes, said data protection system comprising: 
 a command receiving unit which receives a command that requests data processing for data stored in said storage device;    a command storage unit in which one or more valid commands are stored;    a judgment unit which judges whether a command received by said command receiving unit matches one of said valid commands; and    a data processing unit which instructs said storage device to perform data processing requested by said received command when said judgment unit has judged that said received command matches one of said valid commands, and which inhibits said storage device from performing the data processing requested by the received command when said judgment unit has judged that said received command does not match any of said valid commands.    
   
   
       2 . The data protection system according to  claim 1 , wherein said valid commands include a command that requests the data stored in said storage device to be read out.  
   
   
       3 . The data protection system according to  claim 1 , further comprising: 
 an illegal command storage unit in which a command identified as an illegal command is stored when said judgment unit has judged that said command does not match any of said valid commands; and    a saving unit which performs a process to save said illegal command into said illegal command storage unit.    
   
   
       4 . The data protection system according to  claim 1 , wherein said storage device is a memory card, and further comprising a socket to which said memory card is attached.  
   
   
       5 . The data protection system according to  claim 1 , wherein when said judgment unit has judged that said received command does not match any of said valid commands, said data processing unit abandons said received command.  
   
   
       6 . A game machine, comprising: 
 a rewritable storage device;    a game control unit which controls a game by using data stored in said storage device; and    a data protection system;    said data protection system comprising:    a command receiving unit which receives a command from said game control unit that requests data processing for said data stored in said storage device;    a command storage unit in which one or more valid commands are stored;    a judgment unit which judges whether a command received by said command receiving unit matches one of said valid commands; and    a data processing unit which instructs said storage device to perform data processing requested by said received command when said judgment unit has judged that said received command matches one of said valid commands, and which inhibits said storage device from performing the data processing requested by the received command when said judgment unit has judged that said received command does not match any of said valid commands.    
   
   
       7 . The game machine according to  claim 6 , wherein said valid commands include a command which requests the data stored in said storage device to be read out.  
   
   
       8 . The game machine according to  claim 6 , further comprising: 
 an illegal command storage unit in which a command identified as an illegal command is stored when said judgment unit has judged that said command does not match any of said valid commands; and    a saving unit which performs a process to save said illegal command into said illegal command storage unit.    
   
   
       9 . The game machine according to  claim 6 , wherein said storage device is a memory card, and said data protection system further comprises a socket to which said memory card is attached.  
   
   
       10 . The game machine according to  claim 6 , wherein when said judgment unit has judged that said received command does not match any of said valid commands, said data processing unit abandons said received command.  
   
   
       11 . The game machine according to  claim 6 , wherein a game program is stored in said storage device and is run in said game control unit.