COMPUTER SYSTEM AND PROGRAM STARTING METHOD

摘要

PROBLEM TO BE SOLVED: To provide a technology to safely start a program.SOLUTION: An OS program is encrypted or given an electronic signature and stored in a storage of a client device, and the program is obtained from a server device by a boot program which is executed when starting a terminal. The program obtained from the server device is a verification program which decrypts or verifies a signature of an execution object program, and the program is executed after the safety of the OS program is checked by the verification program. When updating the OS program, the server device transmits the reboot program to the client device after downloading the update program. If the safety of the server device is secured, the OS program can be safely started only by securing the safety of communication between client servers without providing a special device to the client device.