# US 12,113,917 B2 · System and method for blockchain platform-based service

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- Number: US 12,113,917 B2
- Document ID: US12113917B2
- Status: Granted
- Kind: B2
- Application number: 17/432,627
- Filed: 2019-02-25
- Published: 2022-05-12
- Granted: 2024-10-08
- Earliest claimed: 2019-02-21
- Assignees: Data Alliance Co., Ltd.
- Applicants: Data Alliance Co., Ltd.
- Inventors: Nam Gyun Kim
- Web page: https://patentgrep.com/patent/US12113917B2

## CPC

- H04L 9/3265: {using certificate chains, trees or paths; Hierarchical trust model}
- G06Q 20/38: Payment protocols; Details thereof
- H04L 9/0825: {using asymmetric-key encryption or public key infrastructure [PKI], e.g. key signature or public key certificates}
- H04L 9/3247: {involving digital signatures}
- H04L 9/3263: {involving certificates, e.g. public key certificate [PKC] or attribute certificate [AC]; Public key infrastructure [PKI] arrangements (network architectures or network communication protocols for supporting authentication of entities using certificates in a packet data network H04L63/0823)}
- H04L 9/50: {using hash chains, e.g. blockchains or hash trees}
- H04L: TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION (arrangements common to telegraphic and telephonic communication H04M)
- G06Q: INFORMATION AND COMMUNICATION TECHNOLOGY [ICT] SPECIALLY ADAPTED FOR ADMINISTRATIVE, COMMERCIAL, FINANCIAL, MANAGERIAL OR SUPERVISORY PURPOSES; SYSTEMS OR METHODS SPECIALLY ADAPTED FOR ADMINISTRATIVE, COMMERCIAL, FINANCIAL, MANAGERIAL OR SUPERVISORY PURPOSES, NOT OTHERWISE PROVIDED FOR

## Abstract

The present disclosure relates to a system and a method for a blockchain platform-based service, the method including generating, at a smart contract deployed on a blockchain platform, a pair of a first private key and a first public key, transmitting the first public key generated at the smart contract to a first computing device, receiving, at the smart contract, data encrypted with the first public key at the first computing device, decrypting, at the smart contract, the encrypted data with the first private key, and storing, at the smart contract, the data decrypted with the first private key as a local variable of the smart contract.

## Claims

### Claim 1

A system for a blockchain platform-based service, the system comprising at least one processor coupled to a storage device storing instructions, the instructions in response to execution by the at least one processor implementing:
a smart contract that is deployed on a blockchain platform and generates a pair of a first private key and a first public key; and
a first computing device that receives the first public key generated in the smart contract and transmits data encrypted with the first public key to the smart contract, wherein
the smart contract decrypts the data encrypted with the first public key with the first private key, and stores the data decrypted with the first private key as a local variable of the smart contract.

### Claim 2 (depends on 1)

The system of claim 1, wherein the data encrypted with the first public key is a private key of a certificate authority.

### Claim 3 (depends on 2)

The system of claim 2, wherein the smart contract issues a certificate that is electronically signed with the private key of the certificate authority stored as the local variable of the smart contract to the blockchain platform.

### Claim 4 (depends on 3)

The system of claim 3, wherein the smart contract receives personal information and a public key of a certificate issuance requester from a second computing device, and issues the certificate by electronically signing a certificate including personal information and a public key of the certificate issuance requester with the private key of the certificate authority.

### Claim 5 (depends on 3)

The system of claim 3, wherein the smart contract stores the issued certificate in the blockchain platform.

### Claim 6

A method for a blockchain platform-based service, comprising:
generating, at a smart contract deployed on a blockchain platform, a pair of a first private key and a first public key;
transmitting the first public key generated at the smart contract to a first computing device;
receiving, at the smart contract, data encrypted with the first public key at the first computing device;
decrypting, at the smart contract, the encrypted data with the first private key; and
storing, at the smart contract, the data decrypted with the first private key as a local variable of the smart contract.

### Claim 7 (depends on 6)

The method of claim 6, wherein the data encrypted with the first public key is a private key of a certificate authority.

### Claim 8 (depends on 7)

The method of claim 7, wherein the smart contract issues a certificate that is electronically signed with the private key of the certificate authority stored as the local variable of the smart contract to the blockchain platform.

### Claim 9 (depends on 8)

The method of claim 8, wherein the smart contract receives personal information and a public key of a certificate issuance requester from a second computing device, and issues the certificate by electronically signing a certificate including personal information and a public key of the certificate issuance requester with the private key of the certificate authority.

### Claim 10 (depends on 8)

The method of claim 8, wherein the smart contract stores the issued certificate in the blockchain platform.