Patent ID: 7443983

Claim:
A communication apparatus which is wirelessly connected to a first terminal and is connected to a plurality of networks corresponding to different security levels and including a first network of a first security level which is a lowest security level of the security levels and a second network of a second security level of the security levels, the communication apparatus comprising: a wireless LAN control unit configured to connect to the first terminal and communicate with the first terminal; and an authentication unit configured to (a) authenticate the first terminal, to (b) select one of the first security level and the second security level based on an authentication result of the first terminal, a first terminal identifier and a first password corresponding to one of the networks, the first terminal identifier and the first password being transmitted from the first terminal and received by the wireless LAN control unit, and to (c) generate, when the second security level is selected, a cryptographic key used in a first cryptographic algorithm corresponding to the second security level, wherein the wireless LAN control unit (a) transmits when the second security level is selected, the cryptographic key and an identifier of the first cryptographic algorithm to the first terminal, (b) transfers, when the second security level is selected, a first data item to the second network and a second data item to the first terminal, the first data item obtained by being encrypted by the first terminal using the first cryptographic algorithm and the cryptographic key, and received from the first terminal, and the second data item addressed to the first terminal and received from the second network; and (c) transfers, when the first security level is selected, a third data item to the first network and a fourth data item to the first terminal, the third data item received from the first terminal, and the fourth data item addressed to the first terminal and received from the first network.