| 摘要 |
PURPOSE: To prevent the use of a software without permission and illegal revision of the software by providing a program number to all programs, generating a cipher on the basis of a program number or a saved date of a program whose use is permitted and registering the generated ciphered data to a storage section of a user side computer as a ledger file. CONSTITUTION: A program number is read out of an external storage device via an input output section 11, and an arithmetic section 12 adds a prescribed number to each digital of a numeral in 4-digit of the program number, for example. Then, the arithmetic section 12 rearranges a program save date in 12-digit, a CPU ID in 8-digit (identification code specific to computer whose use is permitted), and a program number in 4-digit according to a prescribed rule and adds a random number in 1-digit to the result to generate a cipher in 25-digit and the ciphered data are registered in a storage section 13 as a ledger file. The ciphered data are generated for each program whose use is permitted. |
