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Hak-Soo Ju, Suwon-Si KR

Hak-Soo Ju, Suwon-Si KR

Patent application numberDescriptionPublished
20080201782METHOD AND APPARATUS FOR MANAGING DIGITAL CONTENT - A method and apparatus for managing digital content are provided. The apparatus for managing digital content generated by applying digital rights management (DRM) includes: a content execution unit executing digital content; and a control unit confirming whether or not digital content is in a first period in which the digital content can be normally executed, and controlling the content execution unit so that, if the digital content is in the first period, the digital content can be executed normally, and if the digital content is in a second period which is not in the first period, the digital content can be executed in a manner which can be distinguished from that of execution in the first period. According to the apparatus and method, execution of digital content, which is close to expiration, can be controlled, thereby managing the expiration of the digital content for a user.08-21-2008
20080219451METHOD AND SYSTEM FOR MUTUAL AUTHENTICATION BETWEEN MOBILE AND HOST DEVICES - Provided are a method and a system for mutual authentication between mobile and host devices. The mobile device stores a first secret key and is connected to the host device. The method includes generating a second secret key using the first secret key and first data that is received from the host device and is encrypted using a predetermined method. The method further includes transmitting second data that is encrypted using a predetermined method, to the host device to induce generation of a media key; performing an operation on the second secret key and transmitting a generated operation value to the host device; and performing mutual authentication between the mobile device and the host device.09-11-2008
20080226079METHOD AND APPARATUS FOR CONDITIONALLY DECRYPTING CONTENT - Provided is a method of conditionally decrypting content. In the method, whether a content key for encrypting and/or decrypting content is revoked is determined, and encrypted content is selectively decrypted using the content key.09-18-2008
20080229015PORTABLE MEMORY APPARATUS HAVING A CONTENT PROTECTION FUNCTION AND METHOD OF MANUFACTURING THE SAME - A portable memory apparatus having a content protection function is provided. The portable memory apparatus includes a memory and a memory control unit. The memory includes a read-only memory area which stores content and is set to so that only read operations are allowed, a writable memory area which is set so that read and write operations are allowed, and a special memory area which stores information needed to operate the portable memory apparatus and is set so that only authenticated programs are allowed to read from and/or write to the special memory area. The memory control unit controls the read and write operations on each of the areas.09-18-2008
20080229094METHOD OF TRANSMITTING CONTENTS BETWEEN DEVICES AND SYSTEM THEREOF - A method of transmitting content between devices and a system therefor are provided. The method of transmitting encrypted content in a state in which the encrypted content and license information is stored and in which an external device is connected, includes: transmitting the license information corresponding to the encrypted content to the external device; transmitting the encrypted content to the external device, when receiving a request for transmitting the encrypted content from the external device; and updating the license information. Accordingly, content can be rapidly and stably transmitted between the devices. Also, it is possible to improve the accuracy and the security in the procedure of updating the license information.09-18-2008
20080229104MUTUAL AUTHENTICATION METHOD BETWEEN DEVICES USING MEDIATION MODULE AND SYSTEM THEREFOR - A mutual authentication method using a mediation module and a system therefor are provided. The method includes: storing a first partial private key obtained by dividing a first private key of a device; storing a second partial private key obtained by dividing a second private key of a host device; receiving unique identifiers (IDs) and random numbers for the device and the host device from the device and determining whether the unique IDs are valid; and generating a first signature value by using the first partial private key and a second signature value by using the second partial private key if the unique IDs are valid, and transmitting the generated first and second signature values to the device09-18-2008
20090012973APPARATUS AND METHOD FOR IMPORTING CONTENT INCLUDING PLURAL PIECES OF USAGE CONSTRAINT INFORMATION - Provided are a method and apparatus for generating separate rule data using a database management system (DBMS) based language in order to efficiently manage usage rules of content. The method of providing usage rule data of content included in a mobile storage medium connected to a content reproduction device, the method includes: generating first rule data that is a set of rules used to manage the usage rule data based on a data structure of a database management system (DBMS); and generating second rule data that is a set of rules used to access the usage rule data using the first rule data.01-08-2009
20090013172METHOD AND DEVICES FOR REPRODUCING ENCRYPTED CONTENT AND APPROVING REPRODUCTION - A reproduction method capable of immediately revoking a leaked device key by dividing the device key into a first partial key and a second partial key is provided. The reproduction method includes the operations of receiving encrypted content to be reproduced, requesting a token for decrypting the received content from an external device containing a first partial key of a device via a network, receiving the requested token from the external device, and decrypting the received token by using a second partial key contained in the device, thereby preventing content encrypted and distributed before revocation of an illegally copied device from being reproduced, and minimizing damage due to key leakage.01-08-2009
20090016537METHOD OF AUTHENTICATING AND REPRODUCING CONTENT USING PUBLIC BROADCAST ENCRYPTION AND APPARATUS THEREFOR - Provided are a method and apparatus for mutually authenticating devices in a group and reproducing content using public broadcast encryption. The method of authenticating a first device and a second device includes acquiring specific information of the second device from the second device, transmitting data, containing the acquired specific information of the second device and specific information of the first device, by encrypting the data using a broadcast public key of a group to which the second device belongs, and determining whether authentication of the first device succeeds by decrypting the encrypted data by using a private key of the second device. If authentication succeeds, receiving the specific information of the first device, which is encrypted by using a temporary common key by using the decrypted data, and authenticating the second device by decrypting the encrypted specific information of the first device by using the temporary common key.01-15-2009
20090274305METHOD AND APPARATUS FOR TRANSMITTING CONTENT KEY - Provided is a method of transmitting content keys to nodes arranged in a hierarchical structure which includes a plurality of node groups each including a predetermined number of the nodes. In this method, revoke information that includes identifiers of revoked node groups in the hierarchical structure, the total number of independent revoked nodes, and identifiers of the independent revoked nodes is generated. The revoked node groups are node groups consisting of only revoked nodes, and the independent revoked nodes are revoked nodes not belonging to any of the revoked node groups. Then, encrypted content keys are obtained by encrypting content keys using broadcast encryption, by using an encryption key set that has a form that cannot be generated using a decryption key set that the revoked nodes possess, and a set of encrypted content keys is generated. Thereafter, the revoke information and the set of the encrypted content keys are transmitted to all of the nodes arranged in the hierarchical structure.11-05-2009
20090304185METHOD OF TRACING DEVICE KEYS FOR BROADCAST ENCRYPTION - Provided are a method of tracing a device key in a user key management system using a hierarchical hash chain broadcast encryption scheme (HBES) algorithm, a user key management system for executing the method of tracing a device key, and a computer program for executing the method of tracing a device key. The method of tracing a device key of an illegal decoder in a user key management system for broadcast encryption includes: tracing a device key using a binary search; and revoking the traced device key. The technology according to the present invention can be applied to prevent exposure of the device keys to hacking. The present invention provides a method of tracing which can be applied to an HBES algorithm structure.12-10-2009
20100217976METHOD AND APPARATUS FOR IMPORTING CONTENT - A method and apparatus for protecting digital content in a digital rights management (DRM) system are provided. The method of importing a first content file into a second content file includes determining a usage rule of content included in the first content file based on information used to control remote access of the content included in the first content file; and generating the second content file that follows the determined usage rule.08-26-2010
20110138185METHOD AND APPARATUS FOR UPDATING DATA - A method and apparatus for updating data, the method including: receiving a forced update command to forcibly update at least one of a first digital rights management (DRM) module and a first device key stored in the device; receiving a DRM package including at least one of a second DRM module and a second device key based on the forced update command; and updating the at least one of the first DRM module and the first device key based on the received DRM package.06-09-2011

Patent applications by Hak-Soo Ju, Suwon-Si KR