Digital signature certificate method and apparatus therefor

PURPOSE: An electronic signature authenticating method and an electronic signature authenticating device thereof are provided to safely and easily manage an electronic signature by structurizing the electronic signature received from a user and embedding it in a contract information file. CONSTITUTION: A user input unit (104) displays a contract information file and receives an electronic signature from a user. A data extracting unit (112) extracts signature data from the electronic signature and a data converting unit (113) embeds the signature data in the contract information file. The signature data includes a data capacity parameter indicating the whole capacity of the signature data. The data capacity parameter is inserted into right before an end marker of the signature data. When the user input unit receives the electronic signature from the user, the data extracting unit extracts first signature data from the electronic signature. [Reference numerals] (102) Communication interface; (104) User input unit; (106) Display unit; (112) Data extracting unit; (114) Data converting unit; (116) Memory; (120) Control unit