Biblio
Anonymity networks provide privacy to the users by relaying their data to multiple destinations in order to reach the final destination anonymously. Multilayer of encryption is used to protect the users' privacy from attacks or even from the operators of the stations. In this research, we showed how flow analysis could be used to identify encrypted anonymity network traffic under four scenarios: (i) Identifying anonymity networks compared to normal background traffic; (ii) Identifying the type of applications used on the anonymity networks; (iii) Identifying traffic flow behaviors of the anonymity network users; and (iv) Identifying / profiling the users on an anonymity network based on the traffic flow behavior. In order to study these, we employ a machine learning based flow analysis approach and explore how far we can push such an approach.
Traffic classification, i.e. associating network traffic to the application that generated it, is an important tool for several tasks, spanning on different fields (security, management, traffic engineering, R&D). This process is challenged by applications that preserve Internet users' privacy by encrypting the communication content, and even more by anonymity tools, additionally hiding the source, the destination, and the nature of the communication. In this paper, leveraging a public dataset released in 2017, we provide (repeatable) classification results with the aim of investigating to what degree the specific anonymity tool (and the traffic it hides) can be identified, when compared to the traffic of the other considered anonymity tools, using machine learning approaches based on the sole statistical features. To this end, four classifiers are trained and tested on the dataset: (i) Naïve Bayes, (ii) Bayesian Network, (iii) C4.5, and (iv) Random Forest. Results show that the three considered anonymity networks (Tor, I2P, JonDonym) can be easily distinguished (with an accuracy of 99.99%), telling even the specific application generating the traffic (with an accuracy of 98.00%).