Method for managing keys and/or rights objects

A method for controlling use of and/or access to a content file using a rights object in a rights object storage file in a protected area of a storage medium, wherein the content file contains rights object navigation information that indicates location of the rights object in the rights object storage file for controlling use of and/or access to the content file, comprising:

• retrieving the rights object navigation information from a header of the content file after the content file has been opened;
• deriving from the rights object navigation information the location in the rights object storage file in the protected area of the storage device at which the rights object is stored;
• obtaining the rights object from the rights object storage file in the protected area of the storage medium using the derived location;
• and
• controlling use of and/or access to the content file in accordance with the rights object;
• wherein the content file is encrypted, and wherein a key for decrypting the encrypted content file is identified by information in a header of the content file;
• and
• wherein the rights object navigation file is stored in a public memory area, wherein the key is stored in a private memory area, and wherein key management is performed by modifying the rights object navigation file in the public memory area, which does not require access to the private memory area.

A method for controlling use of and/or access to a content file comprising:

• creating a rights object navigation file when such a file does not exist;
• creating at least one rights object storage file when such a file does not exist, wherein each of the entries in the rights object navigation file corresponds to a location for storing one of a plurality of rights objects in the at least one rights object storage file;
• finding in the rights object navigation file an entry other than one that corresponds to a valid rights object in the at least one rights object storage file;
• obtaining from location of said entry in the rights object navigation file rights object navigation information for the content file, obtaining wherein the rights object navigation file is obtained from the content file after the content file has been opened;
• generating a rights object;
• controlling use of and/or access to the content file in accordance with the rights object;
• storing the rights object at a location in the at least one rights object storage file corresponding to the entry;
• wherein the content file is encrypted, and wherein a key for decrypting the encrypted content file is identified by information in a header of the content file;
• and
• wherein the rights object navigation file is stored in a public memory area, wherein the key is stored in a private memory area, and wherein key management is performed by modifying the rights object navigation file in the public memory area, which does not require access to the private memory area.