SECURITY METHOD USING ELECTRONIC SIGNATURE

摘要

A security method using an electronic sign is provided to improve efficiency of the electronic sign authentication by adopting an arbiter for generating/confirming the electronic sign and promote forward security for generating/confirming the electronic sing by attaching the sign of a forward secure SEM(SEMi-trusted party) to a partial sign value generated from a partial secret key of the SEM. A CA(Certificate Authority) generates the secret key formed by a public key and two kinds of pieces according to a request of a user terminal(S420). The generated secret key piece is issued to the user terminal and an arbiter terminal without overlap(S430). If a certificate of the user terminal is validly present, the arbiter server transmits the first sign piece value generated from the received secret key piece to the user terminal(S450). The user terminal generates a signal value by calculating the first sign piece value and the second sign piece value, which is generated by combining the received secret key piece and a value(S460). Validity of the sign value is checked(S470).