Communication device capable of performing a wireless communication according to NFC (abbreviation of near field communication) standard

A non-transitory computer-readable recording medium storing computer-readable instructions for a communication device,

• wherein the computer-readable instructions, when executed by a processor of the communication device, causing the communication device to:
• receive a first specific signal not including authentication information from a first terminal device via an NFC (abbreviation of Near Field Communication) interface in a case where the NFC interface operates in a first operation mode of the NFC standard and the first terminal device operates in a second operation mode of the NFC standard, the NFC interface being configured to perform a wireless communication according to NFC standard, and the first operation mode being for the communication device to receive a signal via the NFC interface;
• change the operation mode of the NFC interface from the first operation mode to a third operation mode of the NFC standard in a case where the first specific signal is received, the third operation mode being for the communication device to send a signal via the NFC interface;
• supply first authentication information to the NFC interface in the case where the first specific signal is received, wherein the NFC interface operates in the third operation mode and sends the first authentication information to the first terminal device;
• store the first authentication information in a memory in the case where the first specific signal is received;
• change the operation mode of the NFC interface from the third operation mode to the first operation mode in a case where the first authentication information has been sent to the first terminal device;
• receive a second specific signal including the first authentication information from the first terminal device via the NFC interface in a case where the NFC interface operates in the first operation mode and the first terminal device operates in the second operation mode after the operation mode of the NFC interface has been changed from the third operation mode to the first operation mode;
• and
• execute an authentication using the first authentication information by determining whether the first authentication information included in the second specific signal is stored in the memory without changing the operation mode of the NFC interface from the first operation mode in a case where the second specific signal is received.

A method performed by a communication device, the method comprising:

• receiving a first specific signal not including authentication information from a first terminal device via an NFC (abbreviation of Near Field Communication) interface in a case where the NFC interface operates in a first operation mode of the NFC standard and the first terminal device operates in a second operation mode of the NFC standard, the NFC interface being configured to perform a wireless communication according to NFC standard, and the first operation mode being for the communication device to receive a signal via the NFC interface;
• changing the operation mode of the NFC interface from the first operation mode to a third operation mode of the NFC standard in a case where the first specific signal is received, the third operation mode being for the communication device to send a signal via the NFC interface;
• supplying first authentication information to the NFC interface in the case where the first specific signal is received, wherein the NFC interface operates in the third operation mode and sends the first authentication information to the first terminal device;
• storing the first authentication information in a memory in the case where the first specific signal is received;
• change the operation mode of the NFC interface from the third operation mode to the first operation mode in a case where the first authentication information has been sent to the first terminal device;
• receiving a second specific signal including the first authentication information from the first terminal device via the NFC interface in a case where the NFC interface operates in the first operation mode and the first terminal device operates in the second operation mode after the operation mode of the NFC interface has been changed from the third operation mode to the first operation mode;
• and
• executing an authentication using the first authentication information by determining whether the first authentication information included in the second specific signal is stored in the memory without changing the operation mode of the NFC interface from the first operation mode in a case where the second specific signal is received.