Abstract: Provided are a method and apparatus for acquiring data regarding a domain for the protection of digital content, and more particularly, a method and apparatus for acquiring domain information and domain-related data in which content received from an external source is converted into content that complies with a set of rules of a digital rights management (DRM) system and a license for the use of the result of the conversion is issued by receiving domain information including a domain key identifier from a domain information providing apparatus and receiving an updated domain key that is a valid domain key currently being used in a domain from a DRM object providing apparatus.

Abstract: A digital content protection apparatus and method for digital rights management (DRM) are provided in which a content file including a plurality of content parts is imported such that a header is included which stores location information required for decoding each of the content parts. Therefore, the number of content parts constituting the content file can be recognized, and a license that is required for the use of each of the content parts can be acquired by analyzing header information without necessitating the parsing of the transport packets of the content file. Accordingly, preparation time for using content can be reduced.

Abstract: A digital content protection apparatus and method for digital rights management (DRM) are provided in which a content file including a plurality of content parts is imported such that a header is included which stores location information required for decoding each of the content parts. Therefore, the number of content parts constituting the content file can be recognized, and a license that is required for the use of each of the content parts can be acquired by analyzing header information without necessitating the parsing of the transport packets of the content file. Accordingly, preparation time for using content can be reduced.

Abstract: A method and apparatus for encrypting or decrypting digital content are provided. In the method, a binding range is selected from a plurality of binding ranges of content use based on license information of the content, and the content is encrypted based on the selected binding range so that the content can be used only within the selected binding range. Accordingly, it is possible to limit content use to a plurality of binding ranges of use of the content, using license information of the content.

Abstract: A content import method in a digital rights management (DRM) system imports transport streams received from outside a domain, generates a content file, and regularly inserts information in the form of transport packets necessary for decrypting encrypted content into a payload of the content file. Accordingly, even if usage constraint information (UCI) included in the received content changes, packaging is possible. When a device pertaining to the domain receives half of an imported content file via streaming, transport packets of the received half of the imported content file can be promptly decrypted without a time delay.

Abstract: A digital content protection apparatus and method for digital rights management (DRM) are provided in which a content file including a plurality of content parts is imported such that a header is included which stores location information required for decoding each of the content parts. Therefore, the number of content parts constituting the content file can be recognized, and a license that is required for the use of each of the content parts can be acquired by analyzing header information without necessitating the parsing of the transport packets of the content file. Accordingly, preparation time for using content can be reduced.

Abstract: A method of measuring round trip time (RTT) and a proximity checking method using the same. The method of measuring RTT includes: transmitting a hashed second random number and starting the RTT measurement; and receiving a hashed first random number from a device that received the hashed second random number and ending the RTT measurement, thereby greatly reducing repetitive encryption and decryption operations in the proximity check using a repetitive RTT measurement.

Abstract: A method and apparatus of protecting digital content within a domain is provided. if a device registered with a domain withdraws from the domain, a domain key used in the domain before withdrawal of the device is updated to a domain key which cannot be used by the device; and the domain key not exposed to the device is transmitted to a plurality of devices currently registered with the domain so that only the currently registered devices have the most recent domain key. Therefore, devices not registered with the domain and devices which previously registered with the home domain but withdrawn from the home domain can be prevented from using digital content currently shared within the domain. In addition, registered devices that withdraw from the home domain may use digital content legitimately downloaded from the home domain before they withdrew from the domain.

Abstract: A revocation key determining method for content protection. The revocation key determining method includes: identifying at least one of a plurality of groups on the basis of a structure in which groups, each consisting of nodes to which key sets for content protection are respectively assigned, are hierarchically arranged in a tree form; and detecting whether nodes belonging to the group are respectively revoked.

Abstract: A method and an apparatus for managing domains are provided. The method of managing one or more domains performed by a domain manager located in a home network includes determining whether to register a first device located in the home network to a domain, and providing data required to share content between the first device and a second device registered to the domain according to the determination. In the method and apparatus, content can be shared by connecting the devices with one another including a user, and the burden of content providers for management can be reduced.

Abstract: A method and an apparatus for transmitting content from a first device that joins a domain to a second device that does not join the domain are provided. If the second device which does not join the domain is adjacent to the first device which joins the domain, by encrypting a content key corresponding to the content to be transmitted to the second device which does not join the domain using a key of the second device which does not join the domain, and then transmitting the content and the encrypted content key to the second device which does not join the domain, the second device which does not join the domain can use the content having an access authority limitation, which can be used by only devices which join the domain.

Abstract: A method and apparatus for protecting digital content in a digital rights management (DRM) system are provided. The method includes: determining a usage bind of content based on usage constraint information of the content; and generating a license of the content for each usage bind. According to the method and apparatus, by generating the license of the content with respect to each usage bind, the content can be protected in a variety of ways with respect to the usage bind of the content, in addition to the conventional content protection by usage constraint information.

Abstract: An apparatus and method for protecting digital content in a digital rights management (DRM) system. In the apparatus and method, usage rules for respective content parts included in a first content file are determined based on plural items of information in the first content file, and a second content file complying with the usage rules is generated. Accordingly, it is possible to allow a user to use only that part of the content included in an externally received content file, which the user has a right to use.

Abstract: A method and apparatus for protecting digital content in a digital rights management (DRM) system. The method of re-importing a second content file, which was imported from a first content file, as a third content file, includes determining whether to allow the re-importing of the second content file based on a difference between a current usage bind of the content determined in an import process and an original usage bind of the content and changing a usage bind of the content from the current usage bind to the original usage bind based on the result of determination. Therefore, when the usage bind of content, which had to be a domain bound, was inevitably determined to be a device bound due to a situation at the time of a content import process, the content can be freely used in the domain bound, which is the original usage bind of the content, according to usage constraints information (UCI) of the content.

Abstract: A method and apparatus for protecting digital content in a digital rights management (DRM) system are provided. The method includes: determining a usage rule for content included in a first content file based on usage constraint information included in the first content file; and generating a second content file complying with this usage rule. According to the method and apparatus, the security requirement of content creators and content providers can be satisfied and at the same time the requirement of content consumers for freer usage can be satisfied.

Abstract: A method of and apparatus for encrypting and/or decrypting content according to broadcast encryption scheme. The decryption method includes: determining whether or not a revoked device among devices that have licenses for predetermined content is present; and according to the determination result, selectively decrypting a content key encrypted by using a key to prevent the revoked device from decrypting the predetermined content. By doing so, an unnecessary encryption process and decryption process that occur when there is no revoked device are avoided.

Abstract: A method and apparatus for managing digital content, which can detect the leakage of an encryption key when the encryption key used for encrypting the digital content is leaked or cracked. When the encrypted digital content is decrypted by an illegal device, a module linked with the encrypted digital content is automatically driven and a digital content managing apparatus is then notified that the encrypted digital content has been decrypted by the illegal device such that the digital content managing apparatus can change the encryption key. Thus, it is possible to prevent the digital content from being continuously leaked due to the use of the same encryption key for encrypting subsequent digital content.

Abstract: A method of measuring round trip time (RTT) includes: chain-hashing at least one random number to create a plurality of hash values; (b) transmitting one of the created hash values to a device and starting to measure RTT of the device; and (c) receiving from the device a response to the transmitted hash value and ending the RTT measurement, thereby performing a more effective proximity check than a conventional proximity check requiring encryptions and decryptions of several tens of times through several thousands of times.

Abstract: A method of packaging broadcast contents are provided. The method includes: extracting a copy control bit from input broadcast contents and determining whether the broadcast contents will be stored after being encrypted based on the extracted copy control bit; creating usage rule information which includes an encryption method of the broadcast contents if it is determined that the broadcast contents will be stored after being encrypted; extracting the copy control bit from each new broadcast content sequentially input and detecting broadcast contents which include copy control bits indicating that the broadcast contents will be stored without being encrypted; and encrypting the input broadcast contents through the broadcast contents before the detected broadcast contents using the encryption method and packaging and storing the encrypted broadcast contents and the usage rule information.

Abstract: A method of backing up domain information relating to the construction of a domain is provided. In the method, the domain information is encrypted and the encrypted domain information is stored in a predetermined storage device in the domain the encrypted domain information to the predetermined storage device, thereby securely backing up the domain information without the help of an external network. Accordingly, even when the existing domain server malfunctions, a new domain server is capable of obtaining the domain information.