Abstract: A method for providing oracle service of a blockchain network by using zero-knowledge proof includes steps of: (a) in response to feeder terminals registering data feeder transactions, including commitments generated with a commitment key and off-chain data, encrypted data generated by encrypting the off-chain data with a public key and data validation values proving with feeder zero-knowledge proof keys that the commitments are identical to the off-chain data, onto the blockchain network, the aggregator terminal acquiring at least one data feeder transaction therefrom; (b) the aggregator terminal verifying data validation values with its corresponding feeder zero-knowledge proof key, decrypting encrypted data with a private key, generating on-chain data from the decrypted data using a calculator and calculation validation values proving with an aggregator zero-knowledge proof key that the on-chain data is generated from the decrypted data, and registering the on-chain data and the calculation validation valu

Abstract: A method for providing oracle service of a blockchain network by using zero-knowledge proof includes steps of: (a) in response to feeder terminals registering data feeder transactions, including commitments generated with a commitment key and off-chain data, encrypted data generated by encrypting the off-chain data with a public key and data validation values proving with feeder zero-knowledge proof keys that the commitments are identical to the off-chain data, onto the blockchain network, the aggregator terminal acquiring at least one data feeder transaction therefrom; (b) the aggregator terminal verifying data validation values with its corresponding feeder zero-knowledge proof key, decrypting encrypted data with a private key, generating on-chain data from the decrypted data using a calculator and calculation validation values proving with an aggregator zero-knowledge proof key that the on-chain data is generated from the decrypted data, and registering the on-chain data and the calculation validation valu

Abstract: A micro device, a micro device alignment apparatus, and an alignment method using the same are proposed. In a micro device that has to be aligned with at least any one surface of front and rear surfaces of the micro device when mounted on a substrate and simultaneously be aligned with any one direction of the micro device when mounted on the substrate, there is provided the micro device, the micro device alignment apparatus, and the alignment method using the same so that surface alignment and direction alignment are simultaneously performed for a plurality of micro devices that is not aligned with at least any one surface of the front and rear surfaces and simultaneously is not aligned with any one direction.

Abstract: A microelement transfer system includes a microelement carrier. The microelement carrier includes a first plate, a second plate, and a microelement support. The first plate has a plurality of first through-holes corresponding to respective microelements. The second plate is provided on the first plate and has a second through-hole having a smaller inner diameter than that of the first through-hole. At least one of the first plate and the second plate is made of an anodic oxide film material. The microelement support includes a carrier substrate on which the microelements are temporarily fixed. The microelement transfer system relatively moves at least one of the microelement carrier and the microelement support in at least one direction so that each of the microelements comes into contact with a side wall of a corresponding one of the first through-holes and detaches to be released from the temporarily fixed state.

Abstract: A blockchain-based personal information management apparatus and method. The blockchain-based personal information management method includes recording, by a first server device, an encrypted value of personal information of a user and a hash value of the personal information in a blockchain, generating, by the first server device, a proof key to be used to generate a personal information proof of the personal information and a verification key to be used to verify the personal information proof based on the personal information, generating, by a blockchain-based personal information management apparatus, the personal information proof from values recorded in the blockchain using the proof key and a prestored prove function related to a zero-knowledge proof, and verifying, by a second server device, the personal information proof from the values recorded in the blockchain using the verification key and a prestored verify function related to the zero-knowledge proof.