RAPTOR: Routing Attacks on Privacy in Tor

The Tor network is a widely used system for anonymous communication. However, Tor is known to be vulnerable to attackers who can observe traffic at both ends of the communication path. In this paper, we show that prior attacks are just the tip of the iceberg. We present a suite of new attacks, called Raptor, that can be launched by Autonomous Systems (ASes) to compromise user anonymity. First, AS-level adversaries can exploit the asymmetric nature of Internet routing to increase the chance of observing at least one direction of user traffic at both ends of the communication. Second, AS-level adversaries can exploit natural churn in Internet routing to lie on the BGP paths for more users over time. Third, strategic adversaries can manipulate Internet routing via BGP hijacks (to discover the users using specific Tor guard nodes) and interceptions (to perform traffic analysis). We demonstrate the feasibility of Raptor attacks by analyzing historical BGP data and Traceroute data as well as performing real-world attacks on the live Tor network, while ensuring that we do not harm real users. In addition, we outline the design of two monitoring frameworks to counter these attacks: BGP monitoring to detect control-plane attacks, and Traceroute monitoring to detect data-plane anomalies. Overall, our work motivates the design of anonymity systems that are aware of the dynamics of Internet routing

A Survey on the Contributions of Software-Defined Networking to Traffic Engineering

Since the appearance of OpenFlow back in 2008, software-defined networking (SDN) has gained momentum. Although there are some discrepancies between the standards developing organizations working with SDN about what SDN is and how it is defined, they all outline traffic engineering (TE) as a key application. One of the most common objectives of TE is the congestion minimization, where techniques such as traffic splitting among multiple paths or advanced reservation systems are used. In such a scenario, this manuscript surveys the role of a comprehensive list of SDN protocols in TE solutions, in order to assess how these protocols can benefit TE. The SDN protocols have been categorized using the SDN architecture proposed by the open networking foundation, which differentiates among data-controller plane interfaces, application-controller plane interfaces, and management interfaces, in order to state how the interface type in which they operate influences TE. In addition, the impact of the SDN protocols on TE has been evaluated by comparing them with the path computation element (PCE)-based architecture. The PCE-based architecture has been selected to measure the impact of SDN on TE because it is the most novel TE architecture until the date, and because it already defines a set of metrics to measure the performance of TE solutions. We conclude that using the three types of interfaces simultaneously will result in more powerful and enhanced TE solutions, since they benefit TE in complementary ways.European Commission through the Horizon 2020 Research and Innovation Programme (GN4) under Grant 691567 Spanish Ministry of Economy and Competitiveness under the Secure Deployment of Services Over SDN and NFV-based Networks Project S&NSEC under Grant TEC2013-47960-C4-3-

Multimedia delivery in the future internet

The term “Networked Media” implies that all kinds of media including text, image, 3D graphics, audio and video are produced, distributed, shared, managed and consumed on-line through various networks, like the Internet, Fiber, WiFi, WiMAX, GPRS, 3G and so on, in a convergent manner [1]. This white paper is the contribution of the Media Delivery Platform (MDP) cluster and aims to cover the Networked challenges of the Networked Media in the transition to the Future of the Internet. Internet has evolved and changed the way we work and live. End users of the Internet have been confronted with a bewildering range of media, services and applications and of technological innovations concerning media formats, wireless networks, terminal types and capabilities. And there is little evidence that the pace of this innovation is slowing. Today, over one billion of users access the Internet on regular basis, more than 100 million users have downloaded at least one (multi)media file and over 47 millions of them do so regularly, searching in more than 160 Exabytes1 of content. In the near future these numbers are expected to exponentially rise. It is expected that the Internet content will be increased by at least a factor of 6, rising to more than 990 Exabytes before 2012, fuelled mainly by the users themselves. Moreover, it is envisaged that in a near- to mid-term future, the Internet will provide the means to share and distribute (new) multimedia content and services with superior quality and striking flexibility, in a trusted and personalized way, improving citizens’ quality of life, working conditions, edutainment and safety. In this evolving environment, new transport protocols, new multimedia encoding schemes, cross-layer inthe network adaptation, machine-to-machine communication (including RFIDs), rich 3D content as well as community networks and the use of peer-to-peer (P2P) overlays are expected to generate new models of interaction and cooperation, and be able to support enhanced perceived quality-of-experience (PQoE) and innovative applications “on the move”, like virtual collaboration environments, personalised services/ media, virtual sport groups, on-line gaming, edutainment. In this context, the interaction with content combined with interactive/multimedia search capabilities across distributed repositories, opportunistic P2P networks and the dynamic adaptation to the characteristics of diverse mobile terminals are expected to contribute towards such a vision. Based on work that has taken place in a number of EC co-funded projects, in Framework Program 6 (FP6) and Framework Program 7 (FP7), a group of experts and technology visionaries have voluntarily contributed in this white paper aiming to describe the status, the state-of-the art, the challenges and the way ahead in the area of Content Aware media delivery platforms

CAIR: Using Formal Languages to Study Routing, Leaking, and Interception in BGP

The Internet routing protocol BGP expresses topological reachability and policy-based decisions simultaneously in path vectors. A complete view on the Internet backbone routing is given by the collection of all valid routes, which is infeasible to obtain due to information hiding of BGP, the lack of omnipresent collection points, and data complexity. Commonly, graph-based data models are used to represent the Internet topology from a given set of BGP routing tables but fall short of explaining policy contexts. As a consequence, routing anomalies such as route leaks and interception attacks cannot be explained with graphs. In this paper, we use formal languages to represent the global routing system in a rigorous model. Our CAIR framework translates BGP announcements into a finite route language that allows for the incremental construction of minimal route automata. CAIR preserves route diversity, is highly efficient, and well-suited to monitor BGP path changes in real-time. We formally derive implementable search patterns for route leaks and interception attacks. In contrast to the state-of-the-art, we can detect these incidents. In practical experiments, we analyze public BGP data over the last seven years

Security analysis of network neighbors

Tese de mestrado em Segurança Informática, apresentada à Universidade de Lisboa, através da Faculdade de Ciências, 2010O presente trabalho aborda um problema comum a muitos dos actuais fornecedores de serviços Internet (ISPs): mitigação eficiente de tráfego malicioso na sua rede. Este tráfego indesejado impõe um desperdício de recursos de rede o que leva a uma consequente degradação da qualidade de serviço. Cria também um ambiente inseguro para os clientes, minando o potencial oferecido pela Internet e abrindo caminho para actividades criminosas graves. Algumas das principais condicionantes na criação de sistemas capazes de resolver estes problemas são: a enorme quantidade de tráfego a ser analisado, o facto da Internet ser inerentemente anónima e a falta de incentivo para os operadores de redes de trânsito em bloquear este tipo de tráfego. No âmbito de um ISP de média escala, este trabalho concentra-se em três áreas principais: origens de tráfego malicioso, classificação de segurança de redes vizinhas ao ISP e políticas de intervenção. Foram colectados dados de rede considerando, determinados tipos de tráfego malicioso: varrimento de endereços e inundação de fluxos de ligações; assim como informação de acessibilidades rede: mensagens de actualização de BGP disponibilizadas pelo RIPE Routing Information Service. Analisámos o tráfego malicioso em busca de padrões de rede, o que nos permitiu compreender que é maioritariamente originário de um subconjunto muito pequeno de ASes na Internet. No âmbito de um ISP e de acordo com um conjunto de métricas de segurança, definimos uma expressão de correlação para quantificar os riscos de segurança associados a conexões com redes vizinhas, a qual denominámos Risk Score. Finalmente, propusemos técnicas para concretização das tarefas de rede necessárias à redução de tráfego malicioso de forma eficiente, se possível em cooperação com redes vizinhas / ASes. Não temos conhecimento de qualquer publicação existente que correlacione as características de tráfego malicioso de varrimento de endereços e inundação de fluxos de ligações, com informação de acessibilidades de rede no âmbito de um ISP, de forma a classificar a segurança das vizinhanças de rede, com o propósito de decidir filtrar o tráfego de prefixos específicos de um AS ou bloquear todo o tráfego proveniente de um AS. Acreditamos que os resultados apresentados neste trabalho podem ser aplicados imediatamente em cenários reais, permitindo criar ambientes de rede mais seguros e escaláveis, desta forma melhorando as condições de rede necessárias ao desenvolvimento de novos serviços.This thesis addresses a common issue to many of current Internet Service Providers (ISPs): efficient mitigation of malicious traffic flowing through their network. This unwanted traffic imposes a waste of network resources, leading to a degradation of quality of service. It also creates an unsafe environment for users, therefore mining the Internet potential and opening way for severe criminal activity. Some of the main constraints of creating systems that may tackle these problems are the enormous amount of traffic to be analyzed, the fact that the Internet is inherently untraceable and the lack of incentive for transit networks to block this type of traffic. Under the scope of a mid scale ISP, this thesis focuses on three main areas: the origins of malicious traffic, security classification of ISP neighbors and intervention policies. We collected network data from particular types of malicious traffic: address scans and flow floods; and network reachability information: BGP update messages from RIPE Routing Information Service (RIS). We analyzed the malicious traffic looking for network patterns, which allowed us to understand that most of it originates from a very small subset of Internet ASes. We defined a correlation expression to quantify the security risks of neighbor connections within an ISP scope according to a set of security metrics that we named Risk Score. We finally proposed techniques to implement the network tasks required to mitigate malicious traffic efficiently, if possible in cooperation with other neighbors/ASes. We are not aware of any work been done that correlates the malicious traffic characteristics of address scans and flow flood attacks, with network reachability information of an ISP network, to classify the security of neighbor connections in order to decide to filter traffic from specific prefixes of an AS, or to block all traffic from an AS. It is our belief, the findings presented in this thesis can be immediately applied to real world scenarios, enabling more secure and scalable network environments, therefore opening way for better deployment environments of new services