According to one embodiment, a communication device includes a first communicator capable of communicating with a server through a first network; a second communicator capable of communicating with an operation terminal of a user through a second network; a first communication processor to execute a first process; a second communication processor to receive, through the second communicator, an issue request, use identification information of the first communication processor, a first key, and a second key paired with the first key to issue a certificate signed by the second key including the identification information of the first communication processor and the first key, sign data to be signed by using a third key to generate signed data, and transmit the signed data and the certificate through the second communicator; and an authorizing processor to acquire permission information indicating permission by the user to issue the certificate.