Abstract: A content distribution system includes a content distribution server and a portable game terminal. The content distribution server retains a first license for comprehensively permitting the use of multiple digital contents and issues to the portable game terminal a second license for individually permitting the use of a digital content selected by a user from among the multiple digital contents. The portable game terminal retains the second license and permits the use of the selected digital content if it is within the license period of the second license at the time.

Abstract: Provided is a content protection system, in which: a user terminal judges, when a content is to be reproduced or executed, whether or not the user terminal has a usage right of the content, and makes, if it is judged that the user terminal does not have the usage right of the content, a request to a license management apparatus to acquire the usage right of the content; the license management apparatus generates, when the request to acquire the usage right is received from the user terminal, license information containing information on an expiration date that is set based on a timing when the request is received, and transmits the generated license information to the user terminal; and the user terminal judges that the user terminal has the usage right of the content until the expiration date indicated by the license information received from the license management apparatus arrives.

Abstract: A version file retrieving unit of a game device retrieves via a network a version file including version information identifying an OS recommended for the execution of game software running. An OS version comparing unit compares first version information on the OS running with second version information identifying the OS recommended for the execution of the game software running. When the second version indicates a version newer than that of the first version information, the OS retrieving unit downloads the latest OS and stores it in the hard disk drive.

Abstract: A content distribution system includes a content distribution server and a portable game terminal. The content distribution server 4-0-retains a first license for comprehensively permitting the use of multiple digital contents and issues to the portable game terminal a second license for individually permitting the use of a digital content selected by a user from among the multiple digital contents. The portable game terminal retains the second license and permits the use of the selected digital content if it is within the license period of the second license at the time.

Abstract: Provided is a content protection system, in which: a user terminal judges, when a content is to be reproduced or executed, whether or not the user terminal has a usage right of the content, and makes, if it is judged that the user terminal does not have the usage right of the content, a request to a license management apparatus to acquire the usage right of the content; the license management apparatus generates, when the request to acquire the usage right is received from the user terminal, license information containing information on an expiration date that is set based on a timing when the request is received, and transmits the generated license information to the user terminal; and the user terminal judges that the user terminal has the usage right of the content until the expiration date indicated by the license information received from the license management apparatus arrives.

Abstract: A version file retrieving unit of a game device retrieves via a network a version file including version information identifying an OS recommended for the execution of game software running. An OS version comparing unit compares first version information on the OS running with second version information identifying the OS recommended for the execution of the game software running. When the second version indicates a version newer than that of the first version information, the OS retrieving unit downloads the latest OS and stores it in the hard disk drive.