A facile and efficient digital signing system. Electronic file in any format can be signed by many persons, dependency relationship between different signatures can be build, signer's advises can be involved in the signature. RSA key (1024 bits) ensures signature safety and dynamic transport encryption protects transported information, login system supports intrusion monitoring and shielding, support anti-counterfeit signature page printing. Records all valid signatures and all wrong logins (existent username but wrong password) for user auditing.