Method and system for payment for central bank digital currency

A payment method of a computer apparatus comprising a first security area, a hardware security module (HSM), and at least one processor, the payment method comprising:

• transmitting, by the at least one processor, a nonce value to a terminal of an end user that is configured to perform a remittance through short-distance communication in an offline situation;
• receiving, by the at least one processor, from the terminal a remittance transaction that is signed using a private key of an HSM of the terminal, the remittance transaction including first last transaction information stored in a second security area of the terminal, the transmitted nonce value, and a hash value of a security value;
• performing, by the at least one processor, signature verification on the received remittance transaction;
• verifying, by the at least one processor, the nonce value included in the received remittance transaction;
• transmitting, by the at least one processor, a verification success message to the terminal in response to a success in the signature verification and verification of the nonce value;
• storing, by the at least one processor, the received remittance transaction and a second last transaction in the first security area;
• and
• receiving, by the at least one processor, an original text of the security value transmitted from the terminal in response to receiving the verification success message.

A computer apparatus comprising:

• at least one processor configured to execute computer-readable instructions;
• a security area;
• and
• a hardware security module (HSM),
• wherein the at least one processor is configured to cause the computer apparatus to,
• receive a nonce value from a terminal of an end user that is to receive a remittance through short-distance communication in an offline situation,
• sign a remittance transaction including first last transaction information stored in the security area, the received nonce value, and a hash value of a security value using a private key of the HSM, and
• transmit the signed remittance transaction to the terminal,
• transmit an original text of the security value of the signed remittance transaction to the terminal, in response to receiving a verification success message from the terminal, and
• store second last transaction information according to the remittance transaction and latest balance of an electronic wallet (E-wallet) in the security area.

A computer apparatus comprising:

• at least one processor configured to execute computer-readable instructions;
• a first security area;
• and
• a hardware security module (HSM),
• wherein the at least one processor is configured to cause the computer apparatus to,
• transmit a nonce value to a terminal of an end user that is configured to perform a remittance through short-distance communication in an offline situation,
• receive, from the terminal, a remittance transaction that is signed using a private key of an HSM of the terminal, the remittance transaction including first last transaction information stored in a second security area of the terminal, the transmitted nonce value, and a hash value of a security value,
• perform signature verification on the received remittance transaction,
• verify the nonce value included in the received remittance transaction,
• transmit a verification success message to the terminal, in response to a success in the signature verification and verification of the nonce value,
• store the received remittance transaction and a second last transaction in the first security area, and
• receive an original text of the security value transmitted from the terminal in response to receiving the verification success message.