COMMUNICATION APPARATUS, COMMUNICATION METHOD, COMMUNICATION SYSTEM, AND COMPUTER PROGRAM

摘要

A measurement to obtain an RTT to a receiving apparatus is performed by a relay apparatus that is disposed between a WAN and a home network and connects these two networks. That an RTT value is equal to or less than the threshold value is set as a content distribution condition from a transmitting apparatus, so that the same use environment as a system using current DLNA and DTCP-IP can be realized for content use in the home network. Thereby, unjust distribution of content is prevented while an authentication and key exchange procedure performed via an external network is allowed.

主权项

1. A communication apparatus comprising:
a data accumulating unit that accumulates transmission data; a communication unit that performs communication with a receiving apparatus becoming a transmission destination of data and a relay apparatus performing relay with the receiving apparatus; a first round trip time information acquiring unit that acquires first round trip time information regarding a first round trip time RTTL between the relay apparatus and the receiving apparatus; an authentication and key exchanging unit that performs authentication and key exchange with the receiving apparatus through the relay apparatus, under a condition of the key exchange where the first round trip time RTTL is equal to or less than a first threshold value; and a data transmitting unit that transmits data encrypted using a key exchanged by the authentication and key exchanging unit to the receiving apparatus.