I. Introduction
THE recent advances of web web services and their enrichment with technologies such as Asynchronous JavaScript with XML (AJAX) have led to a turn from classical desktop software to complex browser enabled web applications. As a result, this rapid development of web web applications, has led to the creation of new attacks that target such services and applications. Computer attacks targeting web services come in two forms: those that exploit a vulnerability of the web service and those that use legitimate means to exhaust the web server's resources. In the first case, the most popular example is probably SQL injection attacks while in the latter, the DoS attacks that target Web services (Web DoS) is a distinctive example.