A method of facilitating, by a portable device, a remote entity to determine whether a person who requests the portable device for access to an IoT device is identical to a person who has been registered as an authorized user of the IoT device, wherein the portable device stores encrypted biometric data or an encrypted combination of pieces of biometric data of the person who has been registered as an authorized user of the IoT device, and the portable device stores a private key concatenated with a verification code that contains: a biometric code generated from biometric data or a combination of pieces of biometric data of the person who has been registered as an authorized user of the IoT device and an IoT device code generated from unique identity data of the IoT device, the method comprising: acquiring biometric data or a combination of pieces of biometric data of a person who requests the portable device for access to the IoT device; determining whether the acquired biometric data or the acquired combination of pieces of biometric data of the person who requests the portable device for access to the IoT device matches the stored encrypted biometric data or the stored encrypted combination of pieces of biometric data of the person who has been registered as the authorized user of the IoT device; creating, based on the private key, authentication information that contains the verification code, when it is determined that they are matched; and transmitting the authentication information to the remote entity, thereby making it possible for the remote entity to determine whether the person who requests the portable device for access to the IoT device is identical to the person who has been registered as the authorized user of the IoT device. generated from unique identity data of the IoT device, the method comprising: acquiring biometric data or a combination of pieces of biometric data of a person who requests the portable device for access to the IoT device; determining whether the acquired biometric data or the acquired combination of pieces of biometric data of the person who requests the portable device for access to the IoT device matches the stored encrypted biometric data or the stored encrypted combination of pieces of biometric data of the person who has acquiring biometric data or a combination of pieces of biometric data of a person who requests the portable device for access to the IoT device; determining whether the acquired biometric data or the acquired combination of pieces of biometric data of the person who requests the portable device for access to the IoT device matches the stored encrypted biometric data or the stored encrypted combination of pieces of biometric data of the person who has been registered as the authorized user of the IoT device; creating, based on the private key, authentication information that contains the verification code, when it is determined that they are matched; and transmitting the authentication information to the remote entity, thereby making it possible for the remote entity to determine whether the person who requests the portable device for access to the IoT device is identical to the person who has been registered as the authorized user of the IoT device. creating, based on the private key, authentication information that contains the verification code, when it is determined that they are matched; and transmitting the authentication information to the remote entity, thereby making it possible for the remote entity to determine whether the person who requests the portable device for access to the IoT device is identical to the person who has been registered as the authorized user of the IoT device.