Abstract: A method of providing video content, the method comprising generating a basement layer and a plurality of enhancement layers by performing scalable video coding on a piece of video content; encrypting the basement layer and the plurality of enhancement layers by using different encryption keys, respectively; and transmitting one of the encryption keys to the second device, together with a video content package that comprises the encrypted basement layer and enhancement layers. The encryption keys include a random encryption key generated randomly and chain encryption keys generated sequentially by performing a Hash function on the random encryption key at least one time.

Abstract: A mutual exclusion method and DRM device is provided. The mutual exclusion method includes receiving an instruction associated with a predetermined stored file from the CE device, checking whether a performing instruction being performed associated with the predetermined stored file exists, and generating a collision error message informing that a collision error has occurred due to the inputted instruction when the performing instruction being performed associated with the predetermined stored file exists.

Abstract: A method of providing a content service and an authentication method between devices using broadcast encryption, a display device, and a resource-constrained device are provided. A method of providing a content service, the method including: transmitting, to a display device, an identification (ID) of a resource-constrained device via the resource-constrained device; receiving encryption information from the display device via the resource-constrained device; and decrypting the encryption information by using a stored secret key set via the resource-constrained device.

Abstract: A method and system for updating time information of a digital rights management (DRM) includes a time server transmitting a time information message to a consumer electronics (CE) device, the CE device transmitting the time information message to a digital rights management DRM device when the CE device receives the time information message from the time server, and the DRM device updating a present time of the DRM device based on the time information message when the DRM device successfully performs authentication with respect to the time information message which has been transmitted from the CE device.

Abstract: A digital rights management (DRM) function performing method and system using a DRM device are provided, in which a DRM device connected to a second communication device decodes encoded contents when a first communication device requests to play the contents, the DRM device re-encodes the contents using a session key, and the DRM device transmits the re-encoded contents to the first communication device via the second communication device.

Abstract: A mutual exclusion method and DRM device is provided. The mutual exclusion method includes receiving an instruction associated with a predetermined stored file from the CE device, checking whether a performing instruction being performed associated with the predetermined stored file exists, and generating a collision error message informing that a collision error has occurred due to the inputted instruction when the performing instruction being performed associated with the predetermined stored file exists.

Abstract: A successive data processing method and apparatus is provided. A data processing apparatus, when connected to a data management apparatus, transmits apparatus information of the data processing apparatus, selects target process data, transmits target process information of the selected target process data, processes the target process data, and transmits process status information according to a process result of the target process data to the data management apparatus.

Abstract: A method and an apparatus are provided for generating an encryption key for broadcast encryption. The method of generating the encryption key for the broadcast encryption includes generating a first encryption key with respect to all nodes, configured in a plurality of depths, from a root node to a plurality of leaf nodes, and generating a second encryption key with respect to each intermediate node between the root node and the plurality of leaf nodes, wherein the generation of the second encryption key comprises generating any one of first and second keys using the first encryption key depending on whether a first child node, connected to a sibling node of the intermediate node, is on a left path or a right path of the intermediate node.

Abstract: A user key allocation method for broadcast encryption is provided. The user key allocation method includes generating a plurality of subsets by dividing one group including a plurality of nodes to sub-groups and allocating key sets with respect to the subsets, respectively. The nodes included in the subset may be odd nodes and even nodes of the nodes of the group. The nodes are arranged so that privileged nodes are consecutive or there is only one privileged node. Accordingly, it is possible to reduce the data size transmitted from the server to the nodes by constituting one or more subsets from the nodes consecutively arranged and providing key sets with respect to the subsets.

Abstract: A communication apparatus having a public key authentication function and a communication method thereof are disclosed. The communication apparatus includes a calculating unit to calculate a first user authentication data for authenticating public information, and a transmitting and receiving unit to transmit the calculated first user authentication data and the public information to be authenticated, and to transmit a password in a form in which a user characteristic input for authenticating the public information is reflected. Accordingly, if the parties to a communication unexpectedly request mutual authentication under an IP-based communication environment, the apparatus can safely authenticate the public information with a use of a user characteristic sensing channel.

Abstract: An improved security device for digital contents and a method for using the security device are provided. The improved security device and method include a transmission and reception unit for transmitting and receiving data necessary for authentication with a mobile device, and for transmitting and receiving contents of the mobile device and a controller for performing authentication with the mobile device, and for decrypting re-encrypted contents from the mobile device when the authentication is successful. The improved method and device provide enhance mobility for users.

Abstract: A mutual authentication apparatus and method for using the Internet, including a user authentication code generator and a server authentication code generator which execute mutual authentication between a user and a server by generating a server authentication code required for the access to the server using an authentication code generating function based on time information provided from a mobile communication network or a global positioning system (GPS) satellite, accessing the server with the generated server authentication code, generating a user authentication code using an authentication code generating function at the accessed server, and providing the generated user authentication code to the user.

Abstract: A method for securely establishing a key against aggressive intervention of a third party. A first device generates a function value using a generator, which is selected from elements in a finite field, and an arbitrary number, which is less than a number of the elements of the finite field, hashes the function value, thereby generating a hashed value, and sends the hashed value and the function value to a second device. The second device hashes the received function value, and establishes a key using the received function value and another arbitrary number selected from the elements of the finite field when the hashed function value matches the received hashed value. Accordingly, it is possible to prevent a third device from intervening in their key establishment. Furthermore, a separate channel for the key establishment is not required because the key is established over a data communication channel.

Abstract: A method of key management in a network system. In a network system which includes at least one node group having a plurality of nodes, the method of key management includes setting commonly-shared keys for subsets of all, or a part of the plurality of nodes; storing a part of the set keys for each node; and generating the rest of the set keys by substituting the part of the set keys for each node in a predetermined function. As a result, the number of keys for storage by each node can be greatly reduced in the transmission of encrypted contents and updated encrypted keys.

Abstract: A system and method of receiving real-time multimedia via a network, includes transmitting a request for the multimedia from a client interface. The request obtains a reply response containing a control message having a first encryption key and a unique software identifier containing an entitlement message, which has a second encryption key. The control message defines content stream information and access criteria, and the entitlement message defines the client interface entitlement rights. The unique software identifier decrypts the multimedia in real-time, in accordance with the content stream information and access criteria, in order to render the multimedia at the client interface.