Computer readable medium on which is stored a program for preventing the unauthorized use of program data

1. A non-transitory storage medium readable by a computer, the storage medium storing a program of instructions executable by the computer to perform a function for preventing unauthorized use of program data, the function comprising:

judging whether an executable code for program data, the program data including encrypted data having been loaded into a memory, is set to be writable; and

executing an unauthorized use prevention process to prevent an unauthorized use of the program data loaded in the memory;

said executing an unauthorized use prevention process including,

modifying a memory attribute of the encrypted data of the program data to writable when the executable code for the program data is not set to be writable,

rewriting the encrypted data of the program data with decrypted data when the executable code for the program data is not set to be writable,

executing the program data in which the encrypted data is rewritten with the decrypted data when the executable code for the program data is not set to be writable, and

executing the program data including the encrypted data when the executable code for the program data is set to be writable.

2. The non-transitory storage medium according to claim 1 , wherein the judging of the executable code is performed based on a descriptor table managed by the computer.

3. The non-transitory storage medium according to claim 1 , wherein the judging of the executable code is performed on the basis of whether an exception for an access violation occurs as a result of executing a process for writing data to the program data.

4. The non-transitory storage medium according to claim 1 , wherein a process for writing data to the program data is executed and the judging of the executable code is performed on the basis of whether a hash value of a data sequence that includes the data stored in the memory remains the same value before and after the process for writing the data.

5. The non-transitory storage medium according to claim 1 , wherein the unauthorized use prevention process stops normal execution of the program data loaded in the memory.

6. The non-transitory storage medium according to claim 1 , wherein the unauthorized use prevention process guards important data or important data handling codes of the program data loaded in the memory.

7. The non-transitory storage medium according to claim 1 , wherein the unauthorized use prevention process transmits a message conveying unauthorized use of the program data loaded in the memory.

8. The non-transitory storage medium according to claim 1 , wherein the function is stored in a tool program and the tool program is embedded in the program data.

9. A non-transitory storage medium readable by a computer, the storage medium storing a program of instructions executable by the computer to perform a function for converting a target program to an unauthorized use prevention program for preventing unauthorized use of program data of the target program, the function comprising:

converting the target program to the unauthorized use prevention program, wherein the unauthorized use prevention program has a process of judging and a process of executing, and the judging process judges whether an executable code for program data, the program data including encrypted data having been loaded into a memory, is set to be writable, and the executing process executes an unauthorized use prevention process to prevent an unauthorized use of the program data loaded in the memory when the executable code for the program data is set to be writable, the executing process executes the unauthorized use prevention process by modifying a memory attribute of the encrypted data of the program data to writable when the executable code for the program data is not set to be writable, rewriting the encrypted data of the program data with decrypted data when the executable code for the program data is not set to be writable, executing the program data in which the encrypted data is rewritten with the decrypted data when the executable code for the program data is not set to be writable, and executing the program data including the encrypted data when the executable code for the program data is set to be writable.

10. A non-transitory storage medium readable by a computer, the storage medium storing a program of instructions executable by the computer to perform a function for preventing unauthorized use of program data, the function comprising:

judging whether an executable code for program data, the program data including compressed data having been loaded into a memory, is set to be writable; and

executing an unauthorized use prevention process to prevent an unauthorized use of the program data loaded in the memory;

said executing an unauthorized use prevention process including,

modifying a memory attribute of the compressed data of the program data to writable when the executable code for the program data is not set to be writable,

rewriting the compressed data of the program data with decompressed data when the executable code for the program data is not set to be writable,

executing the program data in which the compressed data is rewritten with the decompressed data when the executable code for the program data is not set to be writable, and

executing the program data including the compressed data when the executable code for the program data is set to be writable.

11. A non-transitory storage medium readable by a computer, the storage medium storing a program of instructions executable by the computer to perform a function for converting a target program to an unauthorized use prevention program for preventing unauthorized use of program data of the target program, the function comprising:

converting the target program to the unauthorized use prevention program, wherein the unauthorized use prevention program has a process of judging and a process of executing, and the judging process judges whether an executable code for program data, the program data including compressed data having been loaded into a memory, is set to be writable, and the executing process executes an unauthorized use prevention process to prevent an unauthorized use of the program data loaded in the memory when the executable code for the program data is set to be writable, the executing process executes the unauthorized use prevention process by modifying a memory attribute of the compressed data of the program data to writable when the executable code for the program data is not set to be writable, rewriting the compressed data of the program data with decompressed data when the executable code for the program data is not set to be writable, executing the program data in which the compressed data is rewritten with the decompressed data when the executable code for the program data is not set to be writable, and executing the program data including the compressed data when the executable code for the program data is set to be writable.