Patent ID: 7916867

Claim:
A content receiving apparatus which receives a content, comprising: a key exchange unit configured to exchange a first key with a content transmitting apparatus which transmits a content, where the first key being used in encrypting either a content or a second key which encrypts the content and becomes invalid when a time period during which the first key is not used exceeds a first prescribed period; a hardware reception unit configured to receive the content encrypted by using the first key or the second key; a detection unit configured to detect whether the time period during which the first key is not used reaches a second prescribed period which is shorter than the first prescribed period, by counting the time period during which the first key is not used, in the case where reception of the content is suspended; and a transmission unit configured to transmit, when the detection unit detects that the time period during which the first key is not used has reached the second prescribed period, to the content transmitting apparatus, before the first key becomes invalid, information for not making the first key invalid, in the case where reception of the content is suspended, wherein: said detection unit is configured to start counting the time period during which the first key is not used, at a point where a connection with the content transmitting apparatus is disconnected during the reception of the content, or at a point of receiving, from the content transmitting apparatus, a response to the information for not making the first key invalid, and after the reception of the content is resumed, the reception unit is further configured to receive a remaining portion of the content encrypted using the first key or the second key.