摘要:
A scrambling apparatus and method are provided for increasing randomness without damaging compression efficiency of total video data by selectively and randomly performing conversion when converting motion vector codes of compressed video data into other motion vector codes indicating other motion vector values, and more particularly, by performing conditional conversion only if a predetermined condition is satisfied when selective conversion of motion vector codes is performed. The scrambling apparatus includes a conversion motion vector code table generator generating a conversion motion vector code table comprising motion vector codes obtained by converting motion vector codes corresponding to motion vector values of input video data in a standard motion vector code table; and a conversion controller randomly determining whether a certain motion vector value is encoded using the conversion motion vector code table or the standard motion vector code table.
摘要:
A scrambling apparatus and method are provided for increasing randomness without damaging compression efficiency of total video data by selectively and randomly performing conversion when converting motion vector codes of compressed video data into other motion vector codes indicating other motion vector values, and more particularly, by performing conditional conversion only if a predetermined condition is satisfied when selective conversion of motion vector codes is performed. The scrambling apparatus includes a conversion motion vector code table generator generating a conversion motion vector code table comprising motion vector codes obtained by converting motion vector codes corresponding to motion vector values of input video data in a standard motion vector code table; and a conversion controller randomly determining whether a certain motion vector value is encoded using the conversion motion vector code table or the standard motion vector code table.
摘要:
A method and apparatus are provided for simply and securely limiting a number of times that contents can be accessed using a hash chain. The apparatus limiting a number of times contents are accessed by a user terminal includes a hash chain generator receiving information indicating selected contents by the user terminal and information indicating how many times (n) the user terminal has authority to access the selected contents and generating a hash chain including n hash values derived from a seed value, and a contents access manager deleting the hash values one by one from the hash chain whenever the user terminal accesses the selected contents such that the number of times the contents can be accessed by the user terminal is decreased by the number of deleted hash values.
摘要:
A method and apparatus are provided for simply and securely limiting a number of times that contents can be accessed using a hash chain. The apparatus limiting a number of times contents are accessed by a user terminal includes a hash chain generator receiving information indicating selected contents by the user terminal and information indicating how many times (n) the user terminal has authority to access the selected contents and generating a hash chain including n hash values derived from a seed value, and a contents access manager deleting the hash values one by one from the hash chain whenever the user terminal accesses the selected contents such that the number of times the contents can be accessed by the user terminal is decreased by the number of deleted hash values.
摘要:
A home network system allowing a user to directly control joining or removing of member devices in a domain using a user interface and to effectively control a status change of the member devices of the domain and a management method therefor. The home network system includes: a master device, which forms a domain with more than one controlled device, transmits a predetermined domain key to the controlled devices included in the domain, generates a new domain key whenever a configuration of the domain is changed, and transmits the new domain key to the controlled devices remaining in the domain; and a control point, which provides a user interface allowing a user to directly change the configuration of the domain.
摘要:
A home domain building method and system that allow devices to join a home domain using smart cards. In the method, a master device reads device information from a smart card having a device ID and a device key as the device information of a guest device authenticated as a legal device and transmits a challenge request signal to the guest device, the guest device randomly generates a challenge value in response to the challenge request signal, the master device encrypts the challenge value using the device key of the guest device and transmits the encrypted challenge value to the guest device, the guest device decrypts the encrypted challenge value, and if the decrypted challenge value is the same as the challenge value generated in response to the challenge request signal, the guest device allows the master device to join the guest device in the home domain.
摘要:
A home network system allowing a user to directly control joining or removing of member devices in a domain using a user interface and to effectively control a status change of the member devices of the domain and a management method therefor. The home network system includes: a master device, which forms a domain with more than one controlled device, transmits a predetermined domain key to the controlled devices included in the domain, generates a new domain key whenever a configuration of the domain is changed, and transmits the new domain key to the controlled devices remaining in the domain; and a control point, which provides a user interface allowing a user to directly change the configuration of the domain.
摘要:
A home domain building method and system that allow devices to join a home domain using smart cards. In the method, a master device reads device information from a smart card having a device ID and a device key as the device information of a guest device authenticated as a legal device and transmits a challenge request signal to the guest device, the guest device randomly generates a challenge value in response to the challenge request signal, the master device encrypts the challenge value using the device key of the guest device and transmits the encrypted challenge value to the guest device, the guest device decrypts the encrypted challenge value, and if the decrypted challenge value is the same as the challenge value generated in response to the challenge request signal, the guest device allows the master device to join the guest device in the home domain.
摘要:
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.
摘要:
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.