Structured Data (XML, SOAP, AMF, JSON)
The content of traffic between a web browser and a web server consists mainly of HTML files supplemented with images, style sheets and JavaScript files. By contrast, web-based traffic between two servers, between a mobile app and a server or between a JavaScript application running in the browser and the server is typically based on structured data: data whose structure corresponds to a defined scheme and is designed for efficient machine-to-machine communication. This allows a protective instance such as the web application firewall to check the data for suspicious content and also to ensure that the form in which the data is transmitted corresponds to the agreed structure. This validation can play a key part in discovering and neutralizing attacks on a web service.
Examples of structured data types include XML, SOAP (web service calls based on XML), AMF and JSON (Java Script Object Notation).