COMMUNICATION SYSTEM AND COMMUNICATION DEVICE

摘要

A communication apparatus capable of easily identifying a communication partner and securely sharing a session key between the communication apparatus and the communication partner even if the communication apparatus has a processing power that is not so high includes a short-range active communication unit 101 transmitting an inquiry signal to a short-range external communication apparatus by electromagnetic waves and waiting for a response to the inquiry signal; a long-range communication unit 104 capable of communication by the electromagnetic waves in a range wider than the communication area of the short-range active communication means; a switching unit 111 switching to either the short-range active communication unit or the long-range communication unit; and an asymmetric key generator 102 generating a pair of an encryption key and a decryption key corresponding to the encryption key. The communication apparatus is characterized by using the decryption key to decrypt an encrypted session key transmitted from the external communication apparatus and transmitting to the external communication apparatus a communication switching request signal to request the switching to the long-range communication unit and communication by using the long-range communication unit.