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.