Abstract: A lightweight group signature system and method with short signatures according to the exemplary embodiments of the present invention can provide security characteristics similar to group signature mechanisms providing the existing known controllable linkability but can make a revocation method simple by outputting a short signature and providing excellent operation efficiency at the time of signature generation, signature verification, and revocation on smart terminals, and can be widely applied to various anonymity-based application environments, making by making operation efficiency excellent at the time of signature generation and verification and outputting very short signature lengths.

Abstract: The present invention relates to a technique which provides a function of compressed encryption large pieces of plaintext information in a single ciphertext in order to improve a space efficiency of the encryption data which occupies most of a storage space to design an efficient SHE technique which is a base of the FHE technique design. More specifically, the present invention relates to a technique which is designed to improve a structure in which only one bit is encrypted/decrypted in the technique of the prior art to encrypt/decrypt multiple bit information to improve the space efficiency for storing a ciphertext.

Abstract: A system for tracking an illegal distributor and preventing an illegal content distribution includes: a forensic mark generator for receiving content and a content identification code from a content providing apparatus to generate a forensic mark; a forensic mark database for storing the generated forensic mark; a forensic mark insertion unit for inserting the forensic mark into the content; and a content database for storing the content into which the forensic mark has been inserted. The system further includes a content transmitter for transmitting the content into which the forensic mark has been inserted to the content utilization apparatus.

Abstract: Disclosed herein are an apparatus for generating the privacy-protecting document authentication information and a method of performing privacy-protecting document authentication. The apparatus for generating the privacy-protecting document authentication information includes an electronic signature information generation unit, a multi-dimensional code generation unit, and a multi-dimensional code output unit. The electronic signature information generation unit generates electronic signature information for the content of an input document. The multi-dimensional code generation unit generates a multi-dimensional code corresponding to the generated electronic signature information. The multi-dimensional code output unit outputs the generated multi-dimensional code onto the document.

Abstract: A group signature system includes: a key issuer server for generating a first parameter of a group public key, generating a corresponding master issuing key, and issuing a signature key to a user when a user device joins; an opener server for generating a second parameter of the group public key, and a corresponding master opening key and master linking key; and a linker server for checking whether two valid signatures have been linked by using the master linking key when the two signatures corresponding to a group public key are given. The group signature system further includes: a signature verifying unit for confirming a validity of the given signatures and a signer information confirming unit for confirming a validity of singer confirming information generated by the opener server.

Abstract: Disclosed herein are an apparatus and method for anonymity-based authentication and key agreement capable of providing a communication message binding property. The apparatus includes a signature verification unit and a binding checking unit. The signature verification unit receives a plurality of messages, each carrying a signature including link information of a sender, and verifies the signature of each of the plurality of messages. The binding checking unit, if it is determined by the signature verification unit that the signature is valid, determines whether the plurality of messages has been sent by an identical sender based on the link information of the signature.

Abstract: A data encoding apparatus for verifying data integrity by using a white box cipher includes: an encoding unit for encoding content by using a white box cipher table; and an arithmetic logic unit for performing an arithmetic logic operation on the white box cipher table and content information to output an encoded white box cipher table. The arithmetic logic operation is an exclusive OR operation. The content information is license information of the content or hash value of the license information of the content.

Abstract: A content protection apparatus using a white-box encryption table includes: a random number generation unit for generating a random number; a white-box encryption table for encrypting the random number and user information provided from a user to generate an encrypted output value; and an operation unit for performing an operation between the encrypted output value and data inputted from an outside to encrypt or decrypt the data.

Abstract: Disclosed herein is a method of verifying key validity and a server for performing the method. The method is configured such that a service provision server verifies key validity in an anonymous service for providing local linkability. The service provision server receives a revocation list. A local revocation list is generated using the received revocation list and a secret key. A virtual index of a service user required to verify key validity is calculated. Whether a key of the service user is valid is verified, based on whether the virtual index is included in the local revocation list.

Abstract: A broadcast encryption method and a broadcast decryption method. The broadcast encryption method includes generating a message encryption key using a public key and a secret key generated by using a Strong Diffie-Hellman tuple; encrypting a message by the message encryption key; and generating a message header using a sum of a plurality of Strong Diffie-Hellman tuples corresponding to an authorized user group. Accordingly, a transmission amount and a storage amount can be reduced when a broadcast encryption message is transmitted.

Abstract: The present invention relates to a content protection apparatus and method using binding of additional information to an encryption key. The content protection apparatus includes an encryption unit for creating an encryption key required to encrypt data requested by a user terminal and then generating encrypted data in which the data is encrypted. An additional information management unit manages additional information including authority information about the encrypted data. A White-Box Cryptography (WBC) processing unit generates a WBC table required to bind the encryption key corresponding to the encrypted data to the additional information. A bound data generation unit generates bound data in which the encrypted key is bound to the additional information, using a cipher included in the WBC table.

Abstract: A refrigerator is disclosed. The refrigerator includes a cabinet configured to define an exterior boundary of the refrigerator. The refrigerator also includes a first storage chamber defined by interior walls of the cabinet and configured to store food stuffs. The refrigerator further includes a first door configured to open and close the first storage chamber by rotating about a rotational axis. In addition, the refrigerator includes a second storage chamber that is smaller than the first storage chamber defined at a side of the first door, and that is configured to enable access to food stuffs while the first door remains closed and a second door, located in a predetermined portion of the first door, configured to open and close the second storage chamber by rotating the rotational axis, wherein a rotation direction of the second door is identical to the rotation direction of the first door.

Abstract: The present disclosure relates to a refrigerator. The refrigerator includes a cold air generator configured to generate cold air. The refrigerator also includes a first storage chamber configured to receive the cold air generated by the cold air generator. The refrigerator further includes a first storage chamber door configured to open and close an access point to the first storage chamber and configured to store at least one of food and ice stuffs. In addition, the refrigerator includes a second storage chamber, having a container and positioned on the first storage chamber, wherein the second storage chamber is configured to be movable in front and rear directions.

Abstract: A refrigerator is disclosed. The refrigerator includes a cabinet configured to define an exterior boundary of the refrigerator. The refrigerator also includes a first storage chamber defined by interior walls of the cabinet and configured to store food stuffs. The refrigerator further includes a first door configured to open and close the first storage chamber by rotating about a rotational axis. In addition, the refrigerator includes a second storage chamber that is smaller than the first storage chamber defined at a side of the first door, and that is configured to enable access to food stuffs while the first door remains closed and a second door, located in a predetermined portion of the first door, configured to open and close the second storage chamber by rotating the rotational axis, wherein a rotation direction of the second door is identical to the rotation direction of the first door.

Abstract: There is provided an anonymous service method of providing local linkability. The anonymous service method providing local linkability according to exemplary embodiments of the invention, an anonymous authentication operation based on a short group signature is performed, for which the concept of a local linkability is introduced to secure linkability within the same service domain. Namely, in the interior of a service provider, a virtual index having a fixed value is calculated for each service user, and in this case, although a plurality of service providers collude with each other, they cannot calculate a virtual index having the same value, whereby the linkability can be secured within the same service domain but not within the interiors of different service domains.

Abstract: The embodiment relates to a refrigerator. The refrigerator according to one embodiment includes: a cabinet in which a storage chamber is formed; a door that is connected to the cabinet and opens and closes the storage chamber; a receiving member that is mounted in the door and receives foods; a guide unit that guides an up and down movement of the receiving member in a state where the receiving member is mounted in the door; and a fixing unit that fixes a position at which the receiving member is moved.

Abstract: A refrigerator includes a cabinet configured to define an exterior boundary of the refrigerator. The refrigerator also includes a first storage chamber configured to store food stuffs and a first door configured to open and close the first storage chamber. The refrigerator further includes a second storage chamber defined at a side of the first door, and configured to enable access to food stuffs while the first door remains closed and a second door located in a predetermined portion of the first door, and configured to open and close the second storage chamber, wherein a rotation direction of the second door is identical to a rotation direction of the first door.

Abstract: A lightweight group signature system and method with short signatures according to the exemplary embodiments of the present invention can provide security characteristics similar to group signature mechanisms providing the existing known controllable linkability but can make a revocation method simple by outputting a short signature and providing excellent operation efficiency at the time of signature generation, signature verification, and revocation on smart terminals, and can be widely applied to various anonymity-based application environments, making by making operation efficiency excellent at the time of signature generation and verification and outputting very short signature lengths.