Abstract: A refrigerator is provided. The refrigerator includes a cabinet defining a storage space, a drawer type door withdrawably disposed on the cabinet, the drawer type door opening and closing the storage space, a lower receiving member connected to the drawer type door, the lower receiving member being withdrawn together with the drawer type door, an upper receiving member withdrawably disposed above the lower receiving member, and a restraint member disposed on the drawer type door, the restraint member being rotated according to a user's selection to selectively restrain the upper receiving member and to allow the upper receiving member to be selectively interlocked with the drawer type door, thereby selectively withdrawing the upper receiving member.

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: 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: A refrigerator includes a cold air generator configured to generate cold air. The refrigerator also includes a storage chamber configured to receive the cold air generated by the cold air generator, and store at least one food and ice stuffs. Further, the refrigerator includes a storage chamber door configured to open and close an access point to the storage chamber. In addition, the refrigerator includes an inner frame coupled to the storage chamber and configured to move at least a part of the storage chamber in forward and backward directions.

Abstract: Provided is a refrigerator including a height-adjustable receiving apparatus in which a rotation gear is vertically moved along a fixed shaft disposed on a mounting member when the rotation gear disposed on a receiving member is rotated, and the receiving member is adjustable in vertical height. The height-adjustable receiving apparatus includes a receiving member in which foods are received, a mounting member on which the receiving member is vertically movably mounted, a fixed shaft longitudinally disposed on the mounting member, a rotation gear disposed on the receiving member, an operation member disposed on the receiving member, and a transmission member disposed on the receiving member.

Abstract: A method of managing a user key for a broadcast encryption. The method includes assigning numbers to respective users and arranging the users on a ring-shaped structure in order to map hash chains onto the respective nodes of a ring-shaped structure. The method further includes making random node keys correspond to the respective nodes, one by one, constructing the hash chains from the corresponding node keys using a hash function, and successively mapping the constructed hash chains onto the nodes of the ring-shaped structure.

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: A method of managing a user key for a broadcast encryption. The method includes assigning numbers to respective users and arranging the users on a ring-shaped structure in order to map hash chains onto the respective nodes of a ring-shaped structure. The method further includes making random node keys correspond to the respective nodes, one by one, constructing the hash chains from the corresponding node keys using a hash function, and successively mapping the constructed hash chains onto the nodes of the ring-shaped structure.