Data communication system, data communication device, host device, data communication method, and data communication program

A data communication device for communication with a host device, the data communication device comprising:

• a control circuit;
• a memory;
• and
• a communication interface via which to communicate with the host device,
• wherein the control circuit is configured to
• receive inquiry information from the host device, the inquiry information for requesting a unilateral declaration of an encryption scheme,
• transmit encryption information to the host device in response to receiving the inquiry information, the encryption information being related to a previously determined encryption scheme and pre-stored in the memory,
• wherein the transmitted encryption information dictates the encryption scheme to be used by the host device, and
• perform, based on the dictated encryption information, data communication with the host device.

A host device for communication with at least one data communication device, the host device comprising:

• a control circuit;
• and
• a communication interface via which to communicate with the at least one data communication device,
• wherein the control circuit is configured to
• transmit inquiry information to each of the at least one data communication device, the inquiry information for requesting a unilateral declaration of an encryption scheme previously determined in correspondence with the data communication device,
• receive encryption information from each of the at least one data communication device transmitted in response to receiving the inquiry information, the encryption information being related to an encryption scheme corresponding to the data communication device and being pre-stored in the data communication device,
• wherein the transmitted encryption information dictates the encryption scheme to be used by the host device, and
• performs, based on the dictated encryption information, data communication with each of the at least one data communication device.

A data communication method, the data communication method being executable by a computer for causing a data communication device to communicate with a host device, the data communication method comprising:

• receiving inquiry information from the host device, the inquiry information for requesting a unilateral declaration of an encryption scheme;
• transmitting encryption information to the host device in response to receiving the inquiry information, the encryption information being related to a previously determined encryption scheme and being pre-stored in the data communication device;
• wherein the transmitted encryption information dictates the encryption scheme to be used by the host device, and
• performing, based on the dictated encryption information, data communication with the host device.

A data communication method, the data communication method being executable by a computer for causing a host device to communicate with at least one data communication device, the data communication method comprising:

• transmitting inquiry information to each of the at least one data communication device, the inquiry information for requesting a unilateral declaration of an encryption scheme previously determined in correspondence with the data communication device;
• receiving encryption information from each of the at least one data communication device transmitted in response to receiving the inquiry information, the encryption information being related to an encryption scheme corresponding to the data communication device and being pre-stored in the data communication device;
• wherein the transmitted encryption information dictates the encryption scheme to be used by the host device, and
• performing, based on the dictated encryption information, data communication with each of the at least one data communication device.

A non-transitory computer readable storage medium storing a data communication program that, when executed by a computer, causes the computer to perform a method of causing a data communication device to communicate with a host device, the method comprising:

• receiving inquiry information from the host device, the inquiry information for requesting a unilateral declaration of an encryption scheme;
• transmitting encryption information to the host device in response to receiving the inquiry information, the encryption information being related to a previously determined encryption scheme and being pre-stored in the data communication device;
• wherein the transmitted encryption information dictates the encryption scheme to be used by the host device, and
• performing, based on the dictated encryption information, data communication with the host device.

A non-transitory computer readable storage medium storing a data communication program that, when executed by a computer, causes the computer to perform a method of causing a host device to communicate with at least one data communication device, the method comprising:

• transmitting inquiry information to each of the at least one data communication device, the inquiry information for requesting a unilateral declaration of an encryption scheme previously determined in correspondence with the data communication device;
• receiving encryption information from each of the at least one data communication device transmitted in response to receiving the inquiry information, the encryption information being related to an encryption scheme corresponding to the data communication device and being pre-stored in the data communication device;
• wherein the transmitted encryption information dictates the encryption scheme to be used by the host device, and
• performing, based on the dictated encryption information, data communication with each of the at least one data communication device.