The present application generally relates to information processing apparatuses and methods and computer programs. More particularly, the application relates to an information processing apparatus and method and a computer program in which, not only the use of content stored in information recording media, but also the use of data generated or obtained by users afterwards, such as downloaded data, can be controlled on the basis of management units.
Various software data (hereinafter referred to as “content”), such as audio data, e.g., music, image data, e.g., movies, game programs, and various application programs, can be stored on recording media, for example, Blu-ray Discs™ using blue laser light, digital versatile discs (DVDs), mini discs (MDs), compact discs (CDs), as digital data. In particular, Blu-ray discs using blue laser light are high-density recording discs and can record a large volume of video content as high-quality image data.
Digital content is stored in various information recording media, such as those described above, and is provided to users. A user uses the digital content by playing it back on the user's personal computer (PC) or a player, such as a disc player.
Generally, the distribution rights of many content data, such as music data and image data, are owned by creators or sellers of such content data. Basically, therefore, certain usage restrictions are imposed when distributing content, that is, the use of content is allowed only for authorized users, thereby preventing unauthorized copying.
According to digital recording apparatuses and recording media, images and sound can be repeatedly recorded and played back without a loss in quality. Thus, the distribution of illegally copied content via the Internet, the circulation of recording media, such as compact disc recordable (CD-R) discs, recording copied content thereon, so-called “pirated discs”, the use of copied content stored in hard disks of, for example, PCs, are widespread.
DVDs or large-capacity recording media, such as those using blue laser light which have recently been developed, can record a large volume of data, for example, up to several movies, on one medium, as digital information. Since video information can be recorded as digital information as described above, it is becoming important to perform copyright protection by preventing unauthorized copying. Nowadays, to prevent unauthorized copying of digital data, various techniques for preventing unauthorized copying are practically applied to digital recording apparatuses or recording media.
For example, in DVD players, a content scrambling system is employed. According to the content scrambling system, data, such as, video data or sound data, is encrypted and recorded on, for example, a digital versatile disc read only memory (DVD-ROM), and a key for decrypting the encrypted data is supplied to licensed DVD players. A license is given to DVD players that are designed in compliance with predetermined operation rules, for example, agreeing not to perform unauthorized copying. Accordingly, licensed DVD players can decrypt data recorded on a DVD-ROM by using the given key to play back images or sound from the DVD-ROM.
On the other hand, unlicensed DVD players are unable to play back data recorded on the DVD-ROM since they do not have the key for decrypting the encrypted data. In this manner, in the content scrambling system, DVD players that do not satisfy conditions demanded for receiving a license are unable to play back digital data from a DVD-ROM, thereby preventing unauthorized copying.
A management system for content stored in information recording media is constructed, as described above. Another type of system that allows users to easily download content, such as effect sound, moving pictures, and still images, that can serve as materials for video products is disclosed in Japanese Unexamined Patent Application Publication No. 2003-140662. Additionally, a technique for substituting data indicating part of a piece of music with another data is disclosed in Japanese Unexamined Patent Application Publication No. 2002-311967. It is difficult, however, to implement the secure data management or usage management for data generated by executing programs stored in information recording media by users or data or content obtained from external servers.
To perform the secure management for data generated by executing programs stored in information recording media by users or data obtained from external servers, it is necessary to handle individual data by, for example, setting a password for each data by a user input or by encrypting each data by using a cryptographic key obtained from an external source. In this data management structure, however, if the number of data generated or obtained by users afterwards is increased, the number of cryptographic keys or passwords is also increased. Additionally, the location of data becomes unclear and the correspondence between stored data and the cryptographic keys or passwords also becomes unclear. Sufficient measures have not yet been taken for the usage management for such subsequently generated/obtained data.
In particular, in an environment where various application programs can be run, such as in a PC, generally, directories managed by a general-purpose file system are set, and files generated by the corresponding programs can be accessed from various applications. Accordingly, it is preferable that, as well as normal files, subsequently generated/obtained data that should be managed by the content management system be also set in management directories of the general-purpose file system. In this case, however, if special settings are not made, the subsequently generated/obtained data is accessed from various application programs, which cause the unauthorized use or tampering of the data.