TERMINAL DEVICE CONTROL SYSTEM, CONTROL DEVICE, TERMINAL DEVICE, CONTROL METHOD, AND PROGRAM

PROBLEM TO BE SOLVED: To properly control a terminal device according to an arbitrary utilization environment without excessively restricting usability of the terminal device.SOLUTION: A control device outputs encrypted control information acquired by encrypting control information corresponding to encryption condition information by using an encryption key corresponding to encryption key generation information including the encryption condition information. A terminal device acquires utilization environment information indicating its own utilization environment, and outputs decryption key generation information including the utilization environment information. A key management device generates a decryption key corresponding to the decryption key generation information, and outputs the decryption key. The terminal device performs decryption processing on the encrypted control information by using the generated decryption key, and when the control information is acquired, determines whether to permit execution of specific service in the terminal device by using the acquired control information.