The Internet is, undoubtedly, the information highway, where users can access all kinds of data and services quickly and efficiently. However, the Web is a hostile and unsafe environment for users, where privacy is often impossible to assure. There are users that dedicate themselves to browse the Web anonymously and that seek to hide any information that could identify them. These users may also be motivated by more obscure reasons, such as protecting their identity to perpetrate electronic crimes.

In this document, a small survey on e-marketing and the problem of Click Fraud is presented. It serves as motivation for the development of a system that enables the identification of web users who make multiple visits to the same website, in a context in which is assumed that users employ camouflage and concealment techniques, to hide as much information as possible, as a method to prevent identification. The purpose is not to determine the identity of the users or to obtain any kind of private or confidential information. The main goal of the system is to correlate multiple visits of anonymous users, which may seem to have been generated by different users, to understand whether it is a single user who uses cover up techniques. The fundamental rights to privacy and anonymity of users are respected in all instances.

Subsequent to a survey of user tracking techniques and related work, a novel system is proposed, that combines several different techniques. The solution proposed is based on cookies, both HTTP and application types, and on a system for generating digital signatures created from several parameters captured from the user’s machine.

The problem addressed here is a complex one and it is the objective of this work to contribute to its resolution, by proposing a method that enables the identification of users over several Web sessions, seeking to identify all sessions generated by each one.