Patent ID: 8255465

Claim:
A method comprising: at a network processor connected to a local network, intercepting a network communication message originating from a user processor that is different from the network processor connected to the local network and which network communication message is destined for a remote processor connected to the local network via an external network; creating a unique message appendix for the intercepted network communication message to prevent replay attacks on the intercepted network communication message using: message attributes extracted directly from the intercepted network communication message, externally derived attributes derived by querying services external to an encoding agent of the network processor using the extracted message attributes as query parameters, and internally derived attributes derived by querying services internal to the network processor using message attributes as query parameters, wherein the unique message appendix contains information associated with the local network that is available at the local network; encrypting the unique message appendix using a combination of an asymmetric encryption technique that does not require key exchanges and a symmetric encryption technique that is different from the asymmetric encryption technique so that the information in the unique message appendix associated with the local network may be transmitted securely over a public network; encoding the encrypted unique message appendix to allow the unique message appendix to be added to the network communication message without altering the contents of the network communication message; and appending the encoded, encrypted unique message appendix to the network communication message for transmission between the network processor connected to the local network and the remote processor.