Abstract: A multimedia contents service system transforms original contents based on selected user preferences chosen by a user or automatic preferences generated from accumulated statistics on user's contents consumption. The system transmits the transformed contents to the user and provides services which perform rendering or storing according to user preferences. Therefore, the system provides contents transformed according to user's interests to thereby increase user's convenience (universal multimedia access) and satisfy a variety of user's demands.

Abstract: Disclosed are a contents encryption method, and a system and method for providing contents through a network using the contents encryption method. In order to provide contents through the network more securely, at least one piece of contents and corresponding metadata are recursively multi-encrypted at least once, and encrypted data are then provided. In particular, encrypted positions of the contents and corresponding decryption information are expressed as metadata, and the metadata include parameter information on respective encryption tools used for multi-encryption, an order of the applied encryption tools, positions of the encryption tools, and a list of encryption tool substitutes. The metadata are provided when the contents are provided. Therefore, the contents provider and receiver can more safely and systematically manage the metadata including contents decryption information, and multimedia are efficiently protected, managed, and controlled.