TOWARDS RELIABLE CIRCUMVENTION OF INTERNET CENSORSHIP

The Internet plays a crucial role in today\u27s social and political movements by facilitating the free circulation of speech, information, and ideas; democracy and human rights throughout the world critically depend on preserving and bolstering the Internet\u27s openness. Consequently, repressive regimes, totalitarian governments, and corrupt corporations regulate, monitor, and restrict the access to the Internet, which is broadly known as Internet \emph{censorship}. Most countries are improving the internet infrastructures, as a result they can implement more advanced censoring techniques. Also with the advancements in the application of machine learning techniques for network traffic analysis have enabled the more sophisticated Internet censorship. In this thesis, We take a close look at the main pillars of internet censorship, we will introduce new defense and attacks in the internet censorship literature. Internet censorship techniques investigate users’ communications and they can decide to interrupt a connection to prevent a user from communicating with a specific entity. Traffic analysis is one of the main techniques used to infer information from internet communications. One of the major challenges to traffic analysis mechanisms is scaling the techniques to today\u27s exploding volumes of network traffic, i.e., they impose high storage, communications, and computation overheads. We aim at addressing this scalability issue by introducing a new direction for traffic analysis, which we call \emph{compressive traffic analysis}. Moreover, we show that, unfortunately, traffic analysis attacks can be conducted on Anonymity systems with drastically higher accuracies than before by leveraging emerging learning mechanisms. We particularly design a system, called \deepcorr, that outperforms the state-of-the-art by significant margins in correlating network connections. \deepcorr leverages an advanced deep learning architecture to \emph{learn} a flow correlation function tailored to complex networks. Also to be able to analyze the weakness of such approaches we show that an adversary can defeat deep neural network based traffic analysis techniques by applying statistically undetectable \emph{adversarial perturbations} on the patterns of live network traffic. We also design techniques to circumvent internet censorship. Decoy routing is an emerging approach for censorship circumvention in which circumvention is implemented with help from a number of volunteer Internet autonomous systems, called decoy ASes. We propose a new architecture for decoy routing that, by design, is significantly stronger to rerouting attacks compared to \emph{all} previous designs. Unlike previous designs, our new architecture operates decoy routers only on the downstream traffic of the censored users; therefore we call it \emph{downstream-only} decoy routing. As we demonstrate through Internet-scale BGP simulations, downstream-only decoy routing offers significantly stronger resistance to rerouting attacks, which is intuitively because a (censoring) ISP has much less control on the downstream BGP routes of its traffic. Then, we propose to use game theoretic approaches to model the arms races between the censors and the censorship circumvention tools. This will allow us to analyze the effect of different parameters or censoring behaviors on the performance of censorship circumvention tools. We apply our methods on two fundamental problems in internet censorship. Finally, to bring our ideas to practice, we designed a new censorship circumvention tool called \name. \name aims at increasing the collateral damage of censorship by employing a ``mass\u27\u27 of normal Internet users, from both censored and uncensored areas, to serve as circumvention proxies

The devil and packet trace anonymization,”

ABSTRACT Releasing network measurement data-including packet tracesto the research community is a virtuous activity that promotes solid research. However, in practice, releasing anonymized packet traces for public use entails many more vexing considerations than just the usual notion of how to scramble IP addresses to preserve privacy. Publishing traces requires carefully balancing the security needs of the organization providing the trace with the research usefulness of the anonymized trace. In this paper we recount our experiences in (i) securing permission from a large site to release packet header traces of the site's internal traffic, (ii) implementing the corresponding anonymization policy, and (iii) validating its correctness. We present a general tool, tcpmkpub, for anonymizing traces, discuss the process used to determine the particular anonymization policy, and describe the use of meta-data accompanying the traces to provide insight into features that have been obfuscated by anonymization

An investigation to cybersecurity countermeasures for global internet infrastructure.

The Internet is comprised of entities. These entities are called Autonomous Systems (ASes). Each one of these ASes is managed by an Internet Service Provider (ISP). In return each group of ISPs are managed by Regional Internet Registry (RIR). Finally, all RIRs are managed by Internet Assigned Number Authority (IANA). The different ASes are globally connected via the inter-domain protocol that is Border Gateway Protocol (BGP). BGP was designed to be scalable to handle the massive Internet traffic; however, it has been studied for improvements for its lack of security. Furthermore, it relies on Transmission Control Protocol (TCP) which, in return, makes BGP vulnerable to whatever attacks TCP is vulnerable to. Thus, many researchers have worked on developing proposals for improving BGP security, due to the fact that it is the only external protocol connecting the ASes around the globe. In this thesis, different security proposals are reviewed and discussed for their merits and drawbacks. With the aid of Artificial Immune Systems (AIS), the research reported in this thesis addresses Man-In-The-Middle (MITM) and message replay attacks. Other attacks are discussed regarding the benefits of using AIS to support BGP; however, the focus is on MITM and message replay attacks. This thesis reports on the evaluation of a novel Hybrid AIS model compared with existing methods of securing BGP such as S-BGP and BGPsec as well as the traditional Negative Selection AIS algorithm. The results demonstrate improved precision of detecting attacks for the Hybrid AIS model compared with the Negative Selection AIS. Higher precision was achieved with S-BGP and BGPsec, however, at the cost of higher end-to-end delays. The high precision shown in the collected results for S-BGP and BGPsec is largely due to S-BGP encrypting the data by using public key infrastructure, while BGPsec utilises IPsec security suit to encapsulate the exchanged BGP packets. Therefore, neither of the two methods (S-BGP and BGPsec) are considered as Intrusion Detection Systems (IDS). Furthermore, S-BGP and BGPsec lack in the decision making and require administrative attention to mitigate an intrusion or cyberattack. While on the other hand, the suggested Hybrid AIS can remap the network topology depending on the need and optimise the path to the destination

State-of-the-Art Multihoming Protocols and Support for Android

Il traguardo più importante per la connettività wireless del futuro sarà sfruttare appieno le potenzialità offerte da tutte le interfacce di rete dei dispositivi mobili. Per questo motivo con ogni probabilità il multihoming sarà un requisito obbligatorio per quelle applicazioni che puntano a fornire la migliore esperienza utente nel loro utilizzo. Sinteticamente è possibile definire il multihoming come quel processo complesso per cui un end-host o un end-site ha molteplici punti di aggancio alla rete. Nella pratica, tuttavia, il multihoming si è rivelato difficile da implementare e ancor di più da ottimizzare. Ad oggi infatti, il multihoming è lontano dall’essere considerato una feature standard nel network deployment nonostante anni di ricerche e di sviluppo nel settore, poiché il relativo supporto da parte dei protocolli è quasi sempre del tutto inadeguato. Naturalmente anche per Android in quanto piattaforma mobile più usata al mondo, è di fondamentale importanza supportare il multihoming per ampliare lo spettro delle funzionalità offerte ai propri utenti. Dunque alla luce di ciò, in questa tesi espongo lo stato dell’arte del supporto al multihoming in Android mettendo a confronto diversi protocolli di rete e testando la soluzione che sembra essere in assoluto la più promettente: LISP. Esaminato lo stato dell’arte dei protocolli con supporto al multihoming e l’architettura software di LISPmob per Android, l’obiettivo operativo principale di questa ricerca è duplice: a) testare il roaming seamless tra le varie interfacce di rete di un dispositivo Android, il che è appunto uno degli obiettivi del multihoming, attraverso LISPmob; e b) effettuare un ampio numero di test al fine di ottenere attraverso dati sperimentali alcuni importanti parametri relativi alle performance di LISP per capire quanto è realistica la possibilità da parte dell’utente finale di usarlo come efficace soluzione multihoming