ed at the destination node the message is pro- cessed. The processing would involve parsing the message, checking if the message is syntactically correct and identify the action to be performed. Intermediate nodes (nodes between source and destination nodes in a message path) can be added to the message path without changing the parsing and associated message processing logic. Even removing the header, changing the header, reinserting the header, or adding a new header can be performed. There are two types of intermediaries in SOAP. They are the forwarding inter- mediaries and active intermediaries. Forward intermediary performs the basic capability of forwarding the SOAP message to another SOAP node that can be another intermediary or the final destination node. The actions performed by XML-Based Protocols forwarding intermediary is limited to removing of header blocks that are pro- cessed and that which cannot be relayed. Active intermediary performs additional processing that involves modifying the SOAP message before the basic forwarding action. This processing can be related to content manipulation or security related service offering. This additional processing performed by an active SOAP inter- mediary should be marked by inserting a header block to ensure that the changes are detectable by other nodes downstream, which includes intermediaries and the final destination node. SOAP infoset should be serialized and concrete to ensure proper transmission and reconstruction without loss of information. This is achieved using protocol binding of the XML document. An encrypted structure can also provide serializa- tion and is supported in SOAP. The most popular transport binding with SOAP is HTTP. The SOAP-HTTP pair is used extensively in Web-based applications. HTTP binding with SOAP provides request message and response message cor- relation. HTTP implicitly correlates its request message with the response message that can be leveraged as part of binding. So a SOAP application can choose to infer a correlation 