Method, system and its security device for network interworking

A method, a system and its security device for network interworking are provided. The method comprises: the client terminal receiving the operation content inputted by the user; the security device obtaining the operation content; the security device processing the operation content to produce encrypted cryptograph used for recovering the operation content by decryption, and sending the encrypted cryptograph to the client terminal; the client terminal sending the encrypted cryptograph to the server. The method can prevent the operation content from being juggled or forged by Trojan Horse.