摘要:
Not only is it possible to let the viewers watch information that an information provider wants watched by the viewers in a reliable manner, but it is also possible to provide the viewers with information that the information provider desires. A content providing server 1 appends an encryption key ID of an encryption key used when encrypting content data to the content data encrypted using the encryption key and transmits the content data appended with the encryption key ID to a content reproduction device 3, while it transmits the encryption key to a CM providing server 2. The CM providing server 2 embeds the encryption key into CM data and transmits the CM data in which is embedded the encryption key corresponding to the encryption key ID that has been received from the content reproduction device 3 to the content reproduction device 3. The content reproduction device 3 transmits the encryption key ID to the CM providing server 2 and reproduces the CM data received from the CM providing server 2 to decrypt the content data using the encryption key embedded in the CM data, after which it reproduces the decrypted content data.
摘要:
An optical disc recording apparatus (1) includes a system control unit (14) that judges whether main information and sub information which is recorded by being superimposed on said main information, relocates and records the main information or the sub information, or the main information and the sub information in a replacement area, when it is judged to be a defective area, and registers information in a defect management area in the optical disc, the information associating the defective area with the replacement area to which said defective area is relocated.
摘要:
An object is to achieve both the safety and convenience in authentication of an object to be authenticated which is required in various situations. An authentication system (900) includes a first authentication information transmitting device (901) having first authentication information, a second authentication information transmitting device (904) having second authentication information, and an authentication section (905) for authenticating a user or authority of the user. The second authentication information transmitting device (904) sends the second authentication information in only a period during which it receives the first authentication information sent from the first authentication information transmitting device (901). The authentication section (905) receives the second authentication information sent from the second authentication information transmitting device (904), and authenticates the user or the authority of the user based on the second authentication information.