Patent attributes
A system and method for request verification in an Application Level Gateway (ALG) located between a client and a server in a data transmission network. The ALG receives from a server a message that requires some responsive actions from a client. The ALG adds to this message Verification Data (VD) that includes information about expected actions required from the client. The ALG then sends the message with the above-mentioned additions to the client. The client receives this message and sends a response, with the actual actions and with the VD, to the server. The ALG obtains this response with the VD, and compares the description of the expected actions with actual actions of the client. If the actions of the client are legitimate, the ALG sends the client response to the server.
