Patent ID: 8447040

Claim:
A first communication apparatus that functions as one of (i) a providing apparatus that provides an encryption key and (ii) a receiving apparatus that receives an encryption key provided by a providing apparatus, the first communication apparatus comprising: a processor configured to function as a performing unit adapted to perform a key sharing process for sharing an encryption key with another apparatus, wherein the encryption key is used for encrypting information transmitted on a network to which the first communication apparatus and a third communication apparatus belong; a confirmation unit adapted to confirm whether or not the first communication apparatus functioned as the providing apparatus in the key sharing process performed with the third communication apparatus; a comparing unit adapted to compare identification information of a second communication apparatus that has newly joined the network with identification information of the first communication apparatus; a determination unit adapted to determine whether or not the first communication apparatus is to function as a providing apparatus in the key sharing process performed with the second communication apparatus based on the result of the confirmation performed by the confirmation unit and the result of the comparison performed by the comparing unit; and a first notification unit adapted to notify the third communication apparatus of first information or notify the second communication apparatus of second information in the case where the confirmation unit has confirmed that the first communication apparatus functioned as the providing apparatus in the key sharing process with the third communication apparatus and the determination unit determines that the first communication apparatus will not function as the providing apparatus in the key sharing process with the second communication apparatus, wherein the first information is used for identifying the second communication apparatus which becomes a new providing apparatus, and wherein the second information is used for identifying the third communication apparatus which functioned as the receiving apparatus in the key sharing process with the first apparatus.