| 摘要 |
PROBLEM TO BE SOLVED: To provide a password automatic update system which can secure password security by automatically updating a password in a double authentication mode.SOLUTION: At log-in operation, an image selected in pass-image authentication is converted into an encryption key 12 by one-way irreversible arithmetic processing, and encrypted data 13 in a memory 16 is decrypted by the encryption key 12 and converted into a selected internal password PWx. When authentication of the selected internal password PWx is successful, a password authentication unit 15 authorizes the log-in. A password update unit 19 creates a new correct internal password PWk' at specific update timing, notifies a computer internal authentication unit of the new correct internal password PWk', and stores the new correct internal password PWk' in a personal computer 1. Also, the password update unit 19 generates new encrypted data 13a by encrypting the new correct internal password PWk'. An encrypted data registration unit 18 overwrites the old encrypted data 13 by the new encrypted data 13a in the memory 16. |
