Method for encryption and decryption of transaction in power network and system thereof

PURPOSE: Transaction encoding and decoding methods and a system in a power network are provided to effectively reduce a load of system by reducing a coding object while applying a security solution based on a transaction. CONSTITUTION: A transaction serial number is initialized(S100). Transmission data included in the transaction is created. Whether the transmission data is a coding object or not is determined(S120). The transaction serial number is added to the header of a coding object transmission data(S130). A encryption code is obtained from a transmission node or an external server(S140). The coding object transmission data is encrypted using the encryption code(S150). The transmission data is transmitted in a receiving node which receives the transaction(S160).