| 摘要 |
PROBLEM TO BE SOLVED: To attain protection for copyrights, by suppressing illegal copy production, when transmitting contents while using a LAN, and to prevent transmission of the contents from deviating from a range of personal use.SOLUTION: A content transmitting device and a content receiving device perform mutual authentication prior to the transmission of the contents. After mutually confirming that they are apparatuses correctly treating the contents by respecting their copyrights, the contents are transmitted by encrypting the contents with shared key data. When authentication is performed, it is configured to measure the duration of time, until arrival of reception acknowledgement data with respect to transmission of an authentication request or an authentication response. Only when the value of the measured duration of time does not exceed a fixed upper-limit value, is the transmission of the contents performed. According to this, illegal copy production by a device, other than the authenticated content receiver due to reception of the contents by the device is prevented, and the contents are also prevented from being transmitted beyond a wide-area network, or the like. |
