| 摘要 |
PURPOSE:To prevent a copied program from being executed in another computer by using identification numbers different by individual computers to generate a cipher and decipher it. CONSTITUTION:A cipher registering work is performed for the purpose of preventing wrong registration at a software sale time, and the registering processing is performed if results of check of the cipher due to ''input of cipher'' and ''coincidence of cipher?'' are correct. Next, the processing which obtains the identification number of a computer is performed. That is, the processing which uses an identification number (x) to obtain a function f(x) of the number (x) is performed in case of reading of a sequence number added to the computer, and the result is stored in an external cipher file. When the program is started, a result (y) of the function f(x) is taken out from the external cipher file, and the identification number (x) is taken out, and a function g(x, y) of (x) and (y) is obtained. This result g(x, y) is compared with an expected value (z), and the program is stopped if they do not coincide with each other, but the program processing is executed if they coincide. |
