COMMUNICATION DEVICE, COMMUNICATION SYSTEM, AND PROGRAM

摘要

PROBLEM TO BE SOLVED: To rapidly provide an application key for an application with no restriction of quantum cryptography (such as low throughput and its variation).SOLUTION: A communication device comprises: sharing processing unit; an extension unit; and a communication unit. The sharing processing unit shares a first encryption key with an external device with which the communication device is connected via a link, generates a second encryption key and shares the second encryption key with the external device by secret communication using the first encryption key. The extension unit generates an extension key by extending length of the second encryption key. The communication unit transmits the generated extension key to a second application communicating with a first application for which the external device provides the second encryption key.