Abstract: A method for authenticating a specific user by using certificates including a specific certificate of the specific user based on a blockchain network is provided. The method includes steps of: an authentication-supporting server, (a) on condition that a transaction is stored in a distributed database on the blockchain network from when a previous anchoring condition is satisfied to when a current anchoring condition is satisfied, wherein the transaction includes a root hash value created by a Merkle tree operation to leaf nodes having hash values of the certificates and the certificates including public keys of users, root hash identification information, and a transaction ID for locating the transaction on the distributed database are stored in the authentication-supporting server as corresponding to the specific user, if authentication of the specific user is requested, confirming validity of the specific certificate; and (b) if the specific certificate is valid, authenticating the specific user.

Abstract: A method for issuing certificates based on a blockchain network is provided. The method includes steps of: an authentication-supporting server, (a) if personal information on a user is acquired, (i) instructing a user device to generate a public and a private key of the user and transmit the public key to the authentication-supporting server, (ii) storing the certificate including the public hey as corresponding to the personal information, and (iii) determining whether one of current anchoring conditions is satisfied; (b) if it is, generating a root hash value by a Merkle tree operation on leaf nodes including hash values of the certificates stored after a previous anchoring condition is satisfied; and (c) one of (c-1) storing the transaction including the root hash value in a distributed database on the blockchain network and (c-2) instructing a blockchain node to store the transaction in the distributed database, and acquiring a transaction ID.

Abstract: Provided is a method according to the present invention comprising the steps of: (a) generating a message digest of a particular file when a request for authenticating same is obtained; (b) when a message digest encoded with a private key of a first user and a message digest encoded with a private key of a second user are obtained, and if the (i) (A) information for the message digest, which was encoded with the private key of the first user, decoded with a public key of the first user, (ii) (B) information for the message digest, which was encoded with the private key of the second user, decoded with a public key of the second user, and (C) the message digest generated in step (a) match, then registering, in a database, a hash value of the message digest encoded using the private key of the first user, private key of the second user and a private key of a server; and (c) obtaining a transaction ID reflecting location information of the registered hash value in the database.

Abstract: The present invention relates to an accredited certificate issuance system based on a block chain and an accredited certificate issuance method based on block chain using the same, and an accredited certificate authentication system based on a block chain and an accredited certificate authentication method based on a block chain using the same, which disenable a leak of a personal key for accredited certification by autonomously generating, storing and managing the personal key for accredited certification by means of a random number generator mounted in a terminal in which it is impossible to install a function or an additional program for physically accessing and reading the inside of a system; enable a public key for accredited certification, which requires maintenance, to be stored and managed in a block chain of electronic wallets mounted in block chain retention servers via a peer-to-peer (P2P) network-based distribution database, not in a server operated by an accredited certificate authority (CA), and

Abstract: The present invention relates to a system for issuing a public certificate on the basis of a block chain, and a method for issuing a public certificate on the basis of a block chain by using same, the system comprising: a user terminal (100); a server (200) for requesting the issuance of a public certificate on the basis of a block chain; a server (300) for managing the public certificate on the basis of the block chain; and servers (400) having the block chain.

Abstract: A method is provided for providing a notary service for a file, the method including 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 specific user and a private key of the server.

Abstract: The present application provides a tampering verification system and method for financial institution certificates, based on blockchain. Whether or not there is tampering of a certificate in the watermark thereof is verified by comparing the contents of the certificate at the point of first being generated by a financial institution and the point of client issue. Also, in a client certificate registration process, based on blockchain, a means for compressing and registering transaction information comprising client certificate information minimizes the generation of traffic, reduces network overload, and verifies whether there is tampering of certificates of clients of a financial institution, periodically in a predetermined cycle, thus monitoring whether a certificate is being tampered due to hacking.

Abstract: A method is provided for providing a notary service for a file, the method includes 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 for a payment for an Internet of Things (IoT) device is provided. The method includes steps of: a payment supporting server (a) on condition that the payment supporting server has registered certificates of the IoT device, a service providing device, and a digital wallet, and manages corresponding blockchain transaction IDs and link information, if a billing transaction is acquired, validating the billing transaction including identification information on the service providing device and the IoT device, a billing detail, and a signature value; (b) acquiring identification information on the digital wallet corresponding to the billing transaction from the blockchain database; and (c) (i) paying the billing detail using the digital wallet, (ii) registering a payment result including a payment detail in the blockchain database and managing its blockchain transaction ID, and (iii) transmitting the payment result to the service providing device, the IoT device, and the digital wallet.

Abstract: A secure information transmitting system and method for personal identity authentication, which, on the basis of a user public key, encrypt and transmit an authentication number transmitted from a server that provides a service to a user to a mobile communication terminal of the user, thereby preventing an unauthorized user who obtained the authentication number from being recognized even if an authentication number is externally exposed through hacking.

Abstract: A method of a payment for an Internet of Things (IoT) device is provided. The method includes steps of: a payment supporting server (a) on condition that the payment supporting server has registered certificates of the IoT device, a service providing device, and a digital wallet in a first blockchain, manages their transaction IDs, has registered a representative hash value in a second blockchain, manages their transaction IDs, and manages link information between the IoT device and the digital wallet, confirming validity of a billing transaction, and (b) acquiring identification information on the digital wallet; and (c) paying the billing detail using the digital wallet, registering its payment result in the first blockchain, registering in the second blockchain, if one anchoring condition is satisfied, a first representative hash value, and transmitting the payment result to the service providing device, the IoT device, and the digital wallet.

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 relates to a system for issuing a public certificate on the basis of a block chain, and a method for issuing a public certificate on the basis of a block chain by using same, the system comprising: a user terminal (100); a server (200) for requesting the issuance of a public certificate on the basis of a block chain; a server (300) for managing the public certificate on the basis of the block chain; and servers (400) having the block chain.

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: 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: 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: 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 providing a certificate registration service based on a smart contract, wherein the smart contract is source code compilable into executable byte code, is configured to perform procedures if particular conditions are satisfied, and wherein integrity is verified by a consensus, is provided. The method includes steps of: (a) acquiring a public key PubA of a user device, an IdhashA which is hashed personal information, and a VcertA which includes validity conditions, acquiring the smart contract corresponding to the validity conditions and byte code; (b) registering the PubA, the IdhashA and the byte code with a private blockchain database, and acquiring PrivTxidA locating certificate information in the private blockchain database; (c) registering the PrivTxidA and a state of the smart contract with an SDB; and (d) acquiring and registering a hash value calculated using the PubA, the IdhashA and the byte code, and its neighboring hash value.

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: A method for a content providing terminal providing at least one technically protected digital content is disclosed. The method includes steps of: (a) the content providing terminal providing the digital content in which information on a public key or pointing information indicating the information on the public key is embedded, wherein the information on the public key or the pointing information indicating the information on the public key is required to make a digital content provider receive digital money; and (b) the content providing terminal supporting a course of removing a state of restriction on the use of the digital content to allow a user terminal which receives the digital content to play the digital content, if the user terminal creates payment information by using the public key and its private key and the created payment information is determined to be true.