Communication control device and communication system

1. A communication system comprising:

a first communication control device connected between a first device and a network communication network; and

a second communication control device connected between a second device and the network communication network,

the first communication control device including:

a first communication system connected between the first device and the network communication network; and

a second communication system connected between the first device and the network communication network separately from the first communication system,

the first communication system and the second communication system each including:

a first authentication unit;

a first controller configured to request the first authentication unit to perform at least one of a mutual authentication process with the second communication control device using a secret key and a client certificate issued by a private authentication authority or an encryption and decryption process for encrypting information transmitted from the first device to the second device using a common key determined by the first device and the second device, and decrypting information transmitted from the second device to the first device, and to execute communication in a first communication mode for transmitting and receiving plain text data with the first device,

wherein the first controllers of the first communication system and the second communication system execute switching such that one of the communication systems executes communication in the first communication mode, and when a problem is detected in the communication system executing communication in the first communication mode, the other communication system executes communication in the first communication mode, and

the second communication control device including:

a second authentication unit;

a second controller configured to request the second authentication unit to perform at least one of a mutual authentication process with the first communication control device using a secret key and a server certificate issued by the private authentication authority or an encryption and decryption process for encrypting information transmitted from the second device to the first device using a common key determined by the first device and the second device, and decrypting information transmitted from the first device to the second device, and to transmit and receive plain text data with the second device.

2. The communication system according to claim 1 , wherein:

the first communication system and the second communication system are arranged in parallel between the first device and the network communication network; and

when a problem is detected in the communication system executing communication in the first communication mode, the first controllers of the first communication system and the second communication system set the communication system in which the problem is detected to a non-communication state and switch the other communication system to the first communication mode.

3. The communication system according to claim 1 , wherein:

the first communication system and the second communication system are arranged in series between the first device and the network communication network; and

when a problem is detected in the communication system executing communication in the first communication mode, the first controllers of the first communication system and the second communication system set the communication system in which the problem is detected to a second communication mode that allows data to pass through and switch the other communication system to the first communication mode.

4. The communication system according to claim 1 , wherein:

the first communication system and the second communication system each include a communication unit that communicates with a device management server, and

the first controllers of the first communication system and the second communication system transmit, to the device management server, information indicating a problem detected during execution of communication in the first communication mode, and switch the communication system to execute communication in the first communication mode in accordance with an instruction from the device management server.

5. The communication system according to claim 2 , wherein:

the first communication system and the second communication system each include a communication unit that communicates with a device management server, and

the first controllers of the first communication system and the second communication system transmit, to the device management server, information indicating a problem detected during execution of communication in the first communication mode, and switch the communication system to execute communication in the first communication mode in accordance with an instruction from the device management server.

6. The communication system according to claim 3 , wherein:

the first communication system and the second communication system each include a communication unit that communicates with a device management server, and

the first controllers of the first communication system and the second communication system transmit, to the device management server, information indicating a problem detected during execution of communication in the first communication mode, and switch the communication system to execute communication in the first communication mode in accordance with an instruction from the device management server.

7. A communication control device comprising:

a first communication system connected between a first device and a network communication network; and

a second communication system connected between the first device and the network communication network separately from the first communication system,

the first communication system and the second communication system each including:

an authentication unit;

a controller configured to request the authentication unit to perform at least one of a mutual authentication process with a second communication control device connected between the network communication network and a second device using a secret key and a client certificate issued by a private authentication authority or an encryption and decryption process for, encrypting information transmitted from the first device to the second device using a common key determined by the first device and the second device, and decrypting information transmitted from the second device to the first device, and to execute communication in a first communication mode for transmitting and receiving plain text data with the first device,

wherein the controllers of the first communication system and the second communication system execute switching such that one of the communication systems performs communication in the first communication mode, and when a problem is detected in the communication system executing communication in the first communication mode, the other communication system performs communication in the first communication mode.

8. The communication control device according to claim 7 , wherein:

the first communication system and the second communication system are arranged in parallel between the first device and the network communication network; and

when a problem is detected in the communication system executing communication in the first communication mode, the controllers of the first communication system and the second communication system set the communication system in which the problem is detected to a non-communication state and switch the other communication system to the first communication mode.

9. The communication control device according to claim 7 , wherein:

the first communication system and the second communication system are arranged in series between the first device and the network communication network; and

when a problem is detected in the communication system executing communication in the first communication mode, the controllers of the first communication system and the second communication system set the communication system in which the problem is detected to a second communication mode that allows data to pass through, and switch the other communication system to the first communication mode.

10. The communication control device according to claim 7 , wherein:

the first communication system and the second communication system each include a communication unit that communicates with a device management server; and

the controllers of the first communication system and the second communication system transmit, to the device management server, information indicating a problem detected during execution of communication in the first communication mode, and switch the communication system to execute communication in the first communication mode in accordance with an instruction from the device management server.

11. The communication control device according to claim 8 , wherein:

the first communication system and the second communication system each include a communication unit that communicates with a device management server; and

the controllers of the first communication system and the second communication system transmit, to the device management server, information indicating a problem detected during execution of communication in the first communication mode, and switch the communication system to execute communication in the first communication mode in accordance with an instruction from the device management server.

12. The communication control device according to claim 9 , wherein:

the first communication system and the second communication system each include a communication unit that communicates with a device management server; and

the controllers of the first communication system and the second communication system transmit, to the device management server, information indicating a problem detected during execution of communication in the first communication mode, and switch the communication system to execute communication in the first communication mode in accordance with an instruction from the device management server.