Digital asset transaction method

A digital asset transaction method implemented via a connected device, which is directly connectable to the Internet, and a closed device, which is indirectly connectable to the Internet by connecting to the connected device and is able to provide authentication data for permitting the connected device to perform a digital asset transaction, the method comprising:

• a “displaying first check message” step, in which transaction data is generated by the connected device for transacting a desired digital asset, and a first check message with the transaction data is generated by the connected device, and then the first check message is displayed by the connected device;
• a “transmitting transaction data” step, in which a first confirmation instruction is generated by the connected device when the transaction data of the first check message and the desired digital asset match each other, and then the transaction data is transmitted to the closed device from the connected device based on the first confirmation instruction;
• a “displaying second check message” step, in which a second check message with the transaction data is generated by the closed device after receiving the transaction data from the connected device, and then the second check message is displayed by the closed device;
• and
• a “transmitting authentication data” step, in which a second confirmation instruction is generated by the closed device when the transaction data of the second check message and the desired digital asset match each other, and then authentication data, including a second digital signature, is generated by the closed device and is transmitted to the connected device from the closed device based on the second confirmation instruction;
• and
• an “executing transaction” step, in which a transaction authentication is generated by the connected device for executing transaction of the desired digital asset after receiving the second digital signature of the authentication data, and the transaction authentication and the transaction data is transmitted to the transaction system from the connected device for transacting the desired digital asset;
• wherein the closed device includes a security element (SE), the authentication data is stored in the security element, the connected device is permitted to connect to the SE through the MCU, and the second check message is generated by the MCU;
• and
• wherein the second check message is displayed by the closed device after receiving, from the connected device, device pairing data that indicates a pairing between the closed device and the connected device.