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 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: 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: 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 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 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: 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.

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: 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: A method for creating and registering the authentication information is provided. The method includes steps of: (a) an intermediate server determining whether the specific user's public key is registered if (i) the specific user's public key and (ii) a hash value of the specific user's information or its processed value are acquired from the biometric authentication server which received a request for registration of authentication information; and (b) the intermediate server, if the specific user's public key is determined to be unregistered and at least one certain anchoring condition is satisfied, registering with a database a representative hash value or its processed value in a certain data structure, wherein the representative hash value is created by using (1) a specific hash value and (2) at least one hash value of at least one neighboring node which corresponds to a node of the specific hash value.

Abstract: The present invention relates to a digital virtual currency transaction system and method which enable a receiver to make digital virtual currency transactions having a block chain regardless of whether an electronic wallet has been opened, and which have a block chain between concerned parties to guide the concerned parties to be able to conveniently make URL-based transactions without recognizing a public address comprised of 32 bytes or more for every digital virtual currency transaction having a block chain between concerned parties. Provided are a system and a method using same, the system comprising: a block chain-based digital virtual currency transaction guide server (100); a giver terminal (200) which is loaded with a giver-side block chain-based digital virtual currency transaction app (210), generates a giver transaction request signal; and a receiver terminal 300 which clicks the receiver transaction selecting URL (A).

Abstract: A method for creating and registering authentication information is provided. The method includes steps of: (a) an intermediate server determining whether a specific user's public key is registered if (i) the specific user's public key and (ii) a hash value of the specific user's information or its processed value are acquired from a biometric authentication server which received a request for registration; (b) the intermediate server, if the specific user's public key is unregistered, creating and transmitting to a database a transaction whose outputs include (i) the specific user's public key and (ii) the hash value or its processed value (c) the intermediate server acquiring a transaction ID representing location information indicating where the transaction is stored in the database; and (d) the intermediate server notifying the biometric authentication server of a successful registration of (i) the specific user's public key and (ii) the hash value or its processed value.