| 摘要 |
PROBLEM TO BE SOLVED: To make decoding of a password which is set in a printer to be difficult and to sufficiently improve security of the printer. SOLUTION: A personal computer transmits a printer password to the printer at the time of starting. The printer collates the password with the password which is set when it receives the password. When the matching of a collation result is discriminated, the permission notice of a printer operation is transmitted to the computer. When the personal computer receives the permission notice, it starts the control of the printer. At the same time, a clocking operation is started and the password which is set is changed every time 10 seconds are clocked. The changed password is transmitted to the printer. When the printer receives the changed password, it rewrites the printer password which is set to the received password. During printer control, the passwords of the computer and the printer are changed at every ten seconds. |
