Abstract: An embodiment resin composition for shielding electromagnetic waves, based on a total weight of the resin composition, includes 20 to 80 wt % of thermoplastic resin, 1 to 50 wt % of a conductive filler, and 0.1 to 30 wt % of an additive.

Abstract: The present invention provides a method for issuing an electronic voucher, the method comprising: (a) a step in which a server checks whether or not (i) electronic voucher data, (ii) a public key of a specific issuer and (iii) a signature value of the specific issuer are valid; and (b) a step in which, if the validity check result is positive, the server registers or supports the registration of a function value associated with (i) the electronic voucher data, (ii) the public key of the specific issuer and (iii) the signature value of the specific issuer in a blockchain network, and acquires or supports the acquisition of Txid indicating information on the location of the function value, registered in the blockchain network.

Abstract: A method for using authentication information is provided. The method includes steps of: (a) a managing server, if a request for using the authentication information is acquired, acquiring a transaction ID corresponding to a specific user's identification information; (b) the managing server acquiring an output of a specific transaction corresponding to the transaction ID from a blockchain; (c) the managing server determining revocation of the authentication information by referring to the output of the specific transaction; and (d) the managing server supporting a communication by providing the specific user's public key in the output of the specific transaction, if the authentication information is not revoked, and if (i) a hash value of the specific user's identification information included in the output of the specific transaction or its processed value corresponds to (ii) a hash value of the specific user's identification information pre-stored in a certain database or its processed value.

Abstract: The present invention relates to a method for providing an online ticket service by using a blockchain network, comprising steps of: (a) in response to acquiring ticket reservation information corresponding to a ticket purchased by a purchaser from a ticket sale server, creating a ticket token corresponding to the ticket by referring to the ticket reservation information, and registering generated information on the ticket token in a distributed ledger of a blockchain network; and (b) transmitting the ticket token to a seller token wallet corresponding to the seller of the ticket, thereby (i) causing the seller token wallet to transmit the ticket token to a user token wallet corresponding to the user of the ticket, and (ii) registering movement information of the ticket token from the seller token wallet to the user token wallet in the distributed ledger of the blockchain network.

Abstract: Transaction ID information corresponding to proof certificate-verifying transaction information is transmitted to a block chain retention server if a request for proof certificate information is sensed, when the proof certificate-verifying transaction information generated by using the proof certificate information, to be provided to a customer, is recorded in a block chain retention server and the transaction ID information is managed. The proof certificate-verifying transaction information corresponding to the transaction ID information is acquired from the block chain retention server. A proof certificate index hash value used for comparison, acquired from the proof certificate information to be provided to a customer and corresponding to a request, is compared with a proof certificate-verifying index hash value acquired from the proof certificate verifying-transaction information.

Abstract: A method for issuing authentication information is provided. The method includes steps of: (a) a managing server, if identification information of a specific user is acquired from a user device in response to a request for issuing the authentication information and the identification information is determined to be registered, creating a transaction whose output includes: (i) the specific user's public key and (ii) a hash value of the identification information or its processed value to thereby record or support other device to record it on a blockchain; and (b) the managing server acquiring a transaction ID representing location information of the transaction recorded on the blockchain.

Abstract: The present invention provides a method for issuing an electronic voucher, the method comprising: (a) a step in which a server checks whether or not (i) electronic voucher data, (ii) a public key of a specific issuer and (iii) a signature value of the specific issuer are valid; and (b) a step in which, if the validity check result is positive, the server registers or supports the registration of a function value associated with (i) the electronic voucher data, (ii) the public key of the specific issuer and (iii) the signature value of the specific issuer in a blockchain network, and acquires or supports the acquisition of Txid indicating information on the location of the function value, registered in the blockchain network.

Abstract: According to one aspect of the present disclosure, provided is a method for providing a notary service for a file, the method comprising the steps in which: (a) when a notary service request for a specific file is obtained, a server generates, by using a hash function, or supports the generation of, a message digest of the specific file; and (b) if a predetermined condition is satisfied, the server registers, in a database, or supports the registration of, a representative hash value or a value obtained by processing the representative hash value, the representative hash value being generated by calculating at least one neighboring hash value that matches a specific hash value, wherein the specific hash value is a hash value of the result of encrypting the message digest with a private key of a first user, a private key of a second user and a private key of the server.

Abstract: A method of issuing an electronic voucher by an issuer is provided. The method includes steps of: (a) creating and registering a transaction including a voucher data, a public key and a signature value of the issuer, with a private blockchain database, providing the issuer with a PrivTxid locating the transaction in the private blockchain database, and updating and registering value information including a balance of the voucher data with a BDB; and (b) acquiring and registering a representative hash value calculated using a specific hash value, which is a hash value of the voucher data, the public key, and the signature value, and its corresponding hash values which include a hash value of a delta_n including all balances of all vouchers, identifiable by all PrivTxids locating their transactions, with a public blockchain database, and acquiring a Txid locating the representative hash value in the public blockchain database.

Abstract: The present invention relates to a method for providing an online ticket service by using a blockchain network, comprising steps of: (a) in response to acquiring ticket reservation information corresponding to a ticket purchased by a purchaser from a ticket sale server, creating a ticket token corresponding to the ticket by referring to the ticket reservation information, and registering generated information on the ticket token in a distributed ledger of a blockchain network; and (b) transmitting the ticket token to a seller token wallet corresponding to the seller of the ticket, thereby (i) causing the seller token wallet to transmit the ticket token to a user token wallet corresponding to the user of the ticket, and (ii) registering movement information of the ticket token from the seller token wallet to the user token wallet in the distributed ledger of the blockchain network.

Abstract: A method for registering a point distributor and information on an exchange rate for providing a united point service is provided. The method includes steps of: a system managing server (a) verifying a registration transaction TrxA and a confirmation transaction TrxB if at least one of conditions is satisfied which include (i) a condition that the TrxA having (i-1) a public key of a point managing server, and (i-2) a first XEA, an exchange rate of a point A managed by the point distributor to a united point, is acquired from a point distributing server, and (ii) a condition that the TrxB having (ii-1) a public key of the point distributing server, and (ii-2) a second XEA, is acquired from the point managing server; and (b) recording it on a certain blockchain database, and acquiring a transaction ID which locates the TrxA, the TrxB on the certain blockchain database.

Abstract: The present invention provides a method for issuing an electronic voucher, the method comprising: (a) a step in which a server checks whether or not (i) electronic voucher data, (ii) a public key of a specific issuer and (iii) a signature value of the specific issuer are valid; and (b) a step in which, if the validity check result is positive, the server registers or supports the registration of a function value associated with (i) the electronic voucher data, (ii) the public key of the specific issuer and (iii) the signature value of the specific issuer in a public blockchain network, and acquires or supports the acquisition of Txid indicating information on the location of the function value, registered in the public blockchain network, within the public blockchain network.

Abstract: The present invention relates to a method for issuing a currency comprising the steps of: (a) confirming the validity of a currency issuing transaction and a currency issuer, when the currency issuing transaction for issuing the currency from the currency issuer is obtained, the currency issuing transaction including (i) currency receiver information, (ii) issued amount of the currency, (iii) a public key of the currency issuer, and (iv) a signature value of the currency issuer signing the (i), (ii), and (iii) with a private key of the currency issuer; and (b) registering the currency issuing transaction or a function value thereof on a public blockchain network, and obtaining a currency issuance public transaction ID indicating location information of the currency issuing transaction or the function value thereof on the public blockchain network, when the currency issuing transaction and the currency issuer are deemed valid.

Abstract: A method for providing a relational DID (decentralized identifier) service is provided. The method includes steps of: if a specific entity's device broadcasts to a blockchain network a request for registration of relational information which represents a relation between a specific entity's DID and another entity's DID and is set by another entity and confirmed by a specific entity, a blockchain node in the blockchain network (i) verifying the request and registering the relational information in the blockchain network as corresponding to the specific entity's DID and said another entity's DID or (ii) transmitting the request to an identity contract registered in the blockchain network, to allow the identity contract to verify the request and to register the relational information in the blockchain network as corresponding to the specific entity's DID and said another entity's DID.

Abstract: A method for authenticating users contactlessly with decentralized identifiers (DID) using verifiable credentials is provided. The method includes steps of: an authentication supporting server, (a) on condition that a user DID is issued and a user public key is registered in a blockchain network, in response to a contactless authentication request, (i) retrieving the user public key from the blockchain network or from a user DID document sent by a resolving server and (ii) verifying a user signature value; and (b) (i) transmitting real-time feature point information and identity confirmation information to a certification authority (CA) server, (ii) allowing the CA server to transmit authentication result information, (iii) retrieving a CA server public key from the blockchain network or from a CA server DID document sent by the resolving server, (iv) verifying a CA server signature value, (v) registering the authentication result information, and (vi) transmitting a user verifiable credential.

Abstract: A method of registering a point distributor and an exchange rate for a united point service is provided. The method includes steps of: a system managing server (a) verifying a registration transaction TrxA or a confirmation transaction TrxB if (i) a condition that the TrxA having a public key of a point managing server, and a first XEA, an exchange rate of a point A of a point distributor to the united point, is acquired from a point distributing server, or (ii) a condition that the TrxB having a public key of the point distributing server and a second XEA is acquired from the point managing server, is satisfied; and (b) if the TrxA or the TrxB is valid, (i) recording it on a blockchain database, (ii) initializing a balance database by updating a balance of the point distributor, and (iii) acquiring a transaction ID of the TrxA, the TrxB.

Abstract: A method for authenticating users contactlessly with decentralized identifiers (DID) using verifiable credentials is provided. The method includes steps of: an authentication supporting server, (a) on condition that a user DID is issued and a user public key is registered in a blockchain network, in response to a contactless authentication request, (i) retrieving the user public key from the blockchain network or from a user DID document sent by a resolving server and (ii) verifying a user signature value; and (b) (i) transmitting real-time feature point information and identity confirmation information to a certification authority (CA) server, (ii) allowing the CA server to transmit authentication result information, (iii) retrieving a CA server public key from the blockchain network or from a CA server DID document sent by the resolving server, (iv) verifying a CA server signature value, (v) registering the authentication result information, and (vi) transmitting a user verifiable credential.

Abstract: Provided is a method according to one embodiment of the present invention comprising the steps of: (a) a server generating, by means of a hash function, a message digest (MD) of a particular file when a request for authenticating same is obtained; (b) when an MD encoded with a private key of a particular user is obtained, and if (A) information for the MD, which was encoded with the private key of the particular user, decoded with a public key of the particular user matches (B) the MD generated in step (a), then the server registering, in a database, a hash value of the MD encoded with the private key of the particular user and a private key of the server; and (c) the server obtaining a transaction ID.

Abstract: The present invention provides a certificate issuing system based on a block chain, the system having a means for directly generating a certificate-specific public key and a certificate-specific private key in a user terminal operated by a user, guiding the certificate-specific public key and the certificate-specific private key so as to be generated in a state in which a network in the user terminal is blocked, and eliminating the costs incurred for constructing, operating, and maintaining the certificate issuing system having a high-grade security system linked therewith so as to block hacking, which occurred in the past, as much as possible, since the certificate-specific public key requiring maintenance is stored and managed in an electronic wallet, installed in servers that hold block chains, through a peer-to-peer network (P2P)-based distributed database, not by a server run by a certificate authority (CA).

Abstract: The present invention provides a certificate issuing system based on a block chain, the system having a means for directly generating a certificate-specific public key and a certificate-specific private key in a user terminal operated by a user, guiding the certificate-specific public key and the certificate-specific private key so as to be generated in a state in which a network in the user terminal is blocked, and eliminating the costs incurred for constructing, operating, and maintaining the certificate issuing system having a high-grade security system linked therewith so as to block hacking, which occurred in the past, as much as possible, since the certificate-specific public key requiring maintenance is stored and managed in an electronic wallet, installed in servers that hold block chains, through a peer-to-peer network (P2P)-based distributed database, not by a server run by a certificate authority (CA).