Abstract: An encryption key management method includes: receiving a data registration request from a supplier terminal, determining a data identifier associated with the content data, encrypting a master key with a public key of the supplier terminal, and providing the supplier terminal with the master key encrypted with the public key of the supplier terminal, the data identifier, and a key update count value; receiving a subscription application related to the data identifier from a first subscriber terminal, encrypting the master key with a public key of the first subscriber terminal, and providing the first subscriber terminal with the master key encrypted with the public key of the first subscriber terminal and the key update count value; receiving encrypted content data encrypted with the symmetric key and a hash for the content data from the supplier terminal; and transmitting the encrypted content data and the hash to the first subscriber terminal.

Abstract: A Merkle tree-based data management method may comprise: aligning data into two-dimensional square matrix; calculating a hash value of each node of the two-dimensional square matrix; calculating hash values of each row of the two-dimensional square matrix; generating an additional column with nodes having the hash values of each row; calculating hash values of each column of the two-dimensional square matrix; generating an additional row with nodes having hash values of each column; and calculating a Merkle root by concatenating the hash values of the additional column and the hash values of the additional row.

Abstract: A soft sensor includes an elastic sheet, which includes a first elastic layer and a second elastic layer facing each other, and a sensor unit formed by printing a predetermined conductive liquid metal between the first elastic layer and the second elastic layer. A hand-wearable device may include at least one soft sensor, wherein the hand-wearable device has a shape corresponding to at least a portion of a shape of a hand, and the soft sensor is located at a position corresponding to at least some joints of the hand.

Abstract: A data-sharing method, performed by a processor in a data-sharing apparatus including a blockchain ad a data subscription platform server, may comprise: registering, by the data subscription platform server, a data supply plan in the blockchain according to a request of a data supplier; registering, by the data subscription platform server, content data supplied from the data supplier; managing, by the data subscription platform server, data subscription rights of a data subscriber by using the blockchain according to a subscription request of the data subscriber; and supplying, by the data subscription platform server, the content data to the data subscriber.

Abstract: An encryption key management method includes: receiving a data registration request from a supplier terminal, determining a data identifier associated with the content data, encrypting a master key with a public key of the supplier terminal, and providing the supplier terminal with the master key encrypted with the public key of the supplier terminal, the data identifier, and a key update count value; receiving a subscription application related to the data identifier from a first subscriber terminal, encrypting the master key with a public key of the first subscriber terminal, and providing the first subscriber terminal with the master key encrypted with the public key of the first subscriber terminal and the key update count value; receiving encrypted content data encrypted with the symmetric key and a hash for the content data from the supplier terminal; and transmitting the encrypted content data and the hash to the first subscriber terminal.

Abstract: A data tracking method, which is performed by a data tracking apparatus in an edge cloud environment including at least one edge node communicating with an end device and a central cloud, includes receiving data from the end device by a first edge node, creating, by the first edge node, a tracing history and distributing the data to a plurality of edge nodes so as to allow the plurality of edge nodes to create tracing histories, transmitting the created tracing histories to the central cloud by the first edge node and the plurality of edge nodes, and verifying, by the central cloud, linkability of the tracing histories transmitted to the central cloud, storing the tracing histories, analyzing the tracing histories, and providing a data tracking function.

Abstract: A hand-wearable device includes an elastic sheet including a first elastic layer and a second elastic layer facing each other; a sensor unit formed by printing a predetermined conductive liquid metal between the first elastic layer and the second elastic layer; a wire unit extending from the sensor unit and electrically connected to the sensor unit; an electrode substrate formed on one side of the wire unit and spaced apart from the wire unit by a predetermined distance; and a connection electrode formed by printing a predetermined conductive liquid metal between the wire unit and the electrode substrate.

Abstract: A hand-wearable device includes an elastic sheet including a first elastic layer and a second elastic layer facing each other; a sensor unit formed by printing a predetermined conductive liquid metal between the first elastic layer and the second elastic layer; a wire unit extending from the sensor unit and electrically connected to the sensor unit; an electrode substrate formed on one side of the wire unit and spaced apart from the wire unit by a predetermined distance; and a connection electrode formed by printing a predetermined conductive liquid metal between the wire unit and the electrode substrate.

Abstract: A hand-wearable device includes an elastic sheet including a first elastic layer and a second elastic layer facing each other; a sensor unit formed by printing a predetermined conductive liquid metal between the first elastic layer and the second elastic layer; a wire unit extending from the sensor unit and electrically connected to the sensor unit; an electrode substrate formed on one side of the wire unit and spaced apart from the wire unit by a predetermined distance; and a connection electrode formed by printing a predetermined conductive liquid metal between the wire unit and the electrode substrate.

Abstract: A soft sensor includes an elastic sheet, which includes a first elastic layer and a second elastic layer facing each other, and a sensor unit formed by printing a predetermined conductive liquid metal between the first elastic layer and the second elastic layer.

Abstract: A hand-wearable device includes an elastic sheet including a first elastic layer and a second elastic layer facing each other; a sensor unit formed by printing a predetermined conductive liquid metal between the first elastic layer and the second elastic layer; a wire unit extending from the sensor unit and electrically connected to the sensor unit; an electrode substrate formed on one side of the wire unit and spaced apart from the wire unit by a predetermined distance; and a connection electrode formed by printing a predetermined conductive liquid metal between the wire unit and the electrode substrate.