A data transmitting and receiving method for improving transmission and reception efficiency can be obtained by improving the security through update of a control key and reduction of the frequency of the authentication and key exchange process. An STB 1 transmits encrypted digital data Kw (D) obtained...http://www.google.ca/patents/US6834111?utm_source=gb-gplus-sharePatent US6834111 - DATA TRANSMITTING/RECEIVING METHOD, DATA TRANSMITTER, DATA RECEIVER, DATA TRANSMITTING/RECEIVING SYSTEM, AV CONTENT TRANSMITTING METHOD, AV CONTENT RECEIVING METHOD, AV CONTENT TRANSMITTER, AV CONTENT RECEIVER, AND PROGRAM RECORDING MEDIUM
