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

Securing Internet Applications from Routing Attacks

Attacks on Internet routing are typically viewed through the lens of availability and confidentiality, assuming an adversary that either discards traffic or performs eavesdropping. Yet, a strategic adversary can use routing attacks to compromise the security of critical Internet applications like Tor, certificate authorities, and the bitcoin network. In this paper, we survey such application-specific routing attacks and argue that both application-layer and network-layer defenses are essential and urgently needed. While application-layer defenses are easier to deploy in the short term, we hope that our work serves to provide much needed momentum for the deployment of network-layer defenses

ROVER: a DNS-based method to detect and prevent IP hijacks

2013 Fall.Includes bibliographical references.The Border Gateway Protocol (BGP) is critical to the global internet infrastructure. Unfortunately BGP routing was designed with limited regard for security. As a result, IP route hijacking has been observed for more than 16 years. Well known incidents include a 2008 hijack of YouTube, loss of connectivity for Australia in February 2012, and an event that partially crippled Google in November 2012. Concern has been escalating as critical national infrastructure is reliant on a secure foundation for the Internet. Disruptions to military, banking, utilities, industry, and commerce can be catastrophic. In this dissertation we propose ROVER (Route Origin VERification System), a novel and practical solution for detecting and preventing origin and sub-prefix hijacks. ROVER exploits the reverse DNS for storing route origin data and provides a fail-safe, best effort approach to authentication. This approach can be used with a variety of operational models including fully dynamic in-line BGP filtering, periodically updated authenticated route filters, and real-time notifications for network operators. Our thesis is that ROVER systems can be deployed by a small number of institutions in an incremental fashion and still effectively thwart origin and sub-prefix IP hijacking despite non-participation by the majority of Autonomous System owners. We then present research results supporting this statement. We evaluate the effectiveness of ROVER using simulations on an Internet scale topology as well as with tests on real operational systems. Analyses include a study of IP hijack propagation patterns, effectiveness of various deployment models, critical mass requirements, and an examination of ROVER resilience and scalability

Interdomain Route Leak Mitigation: A Pragmatic Approach

The Internet has grown to support many vital functions, but it is not administered by any central authority. Rather, the many smaller networks that make up the Internet - called Autonomous Systems (ASes) - independently manage their own distinct host address space and routing policy. Routers at the borders between ASes exchange information about how to reach remote IP prefixes with neighboring networks over the control plane with the Border Gateway Protocol (BGP). This inter-AS communication connects hosts across AS boundaries to build the illusion of one large, unified global network - the Internet. Unfortunately, BGP is a dated protocol that allows ASes to inject virtually any routing information into the control plane. The Internet’s decentralized administrative structure means that ASes lack visibility of the relationships and policies of other networks, and have little means of vetting the information they receive. Routes are global, connecting hosts around the world, but AS operators can only see routes exchanged between their own network and directly connected neighbor networks. This mismatch between global route scope and local network operator visibility gives rise to adverse routing events like route leaks, which occur when an AS advertises a route that should have been kept within its own network by mistake. In this work, we explore our thesis: that malicious and unintentional route leaks threaten Internet availability, but pragmatic solutions can mitigate their impact. Leaks effectively reroute traffic meant for the leak destination along the leak path. This diversion of flows onto unexpected paths can cause broad disruption for hosts attempting to reach the leak destination, as well as obstruct the normal traffic on the leak path. These events are usually due to misconfiguration and not malicious activity, but we show in our initial work that vrouting-capable adversaries can weaponize route leaks and fraudulent path advertisements to enhance data plane attacks on Internet infrastructure and services. Existing solutions like Internet Routing Registry (IRR) filtering have not succeeded in solving the route leak problem, as globally disruptive route leaks still periodically interrupt the normal functioning of the Internet. We examine one relatively new solution - Peerlocking or defensive AS PATH filtering - where ASes exchange toplogical information to secure their networks. Our measurements reveal that Peerlock is already deployed in defense of the largest ASes, but has found little purchase elsewhere. We conclude by introducing a novel leak defense system, Corelock, designed to provide Peerlock-like protection without the scalability concerns that have limited Peerlock’s scope. Corelock builds meaningful route leak filters from globally distributed route collectors and can be deployed without cooperation from other network

Impact of prefix hijacking on payments of providers

Abstract—Whereas prefix hijacking is usually examined from security perspectives, this paper looks at it from a novel economic angle. Our study stems from an observation that a transit AS (Autonomous System) has a financial interest in attracting extra traffic to the links with its customers. Based on real data about the actual hijacking incident in the Internet, we conduct simulations in the real AS-level Internet topology with synthetic demands for the hijacked traffic. Then, we measure traffic on all inter-AS links and compute the payments of all providers. The analysis of our results from technical, business, and legal viewpoints suggests that hijacking-based traffic attraction is a viable strategy that can create a fertile ground for tussles between providers. In particular, giant top-tier providers appear to have the strongest financial incentives to hijack popular prefixes and then deliver the intercepted traffic to the proper destinations. We also discuss directions for future research in the area of hijacking-based traffic attraction

Análise da Implantação do RPKI no Brasil

Sequestro de prefixos é um problema que enfrentamos atualmente na internet que pode levar a indisponibilidade de um ASN ou roubo de informações. Existem diversas ferramentas para se proteger desse tipo de ataque, sendo o RPKI o mais promissor, onde é criado certificados digitais para autorizar um ASN a anunciar determinado prefixo e o Brasil está adotando esta solução. Neste trabalho de conclusão analisamos o crescimento da implantação do RPKI neste primeiro ano de adoção no Brasil. Também correlacionamos informações que mostram que os treinamentos para utilização dessa ferramenta têm impulsionado significativamente para o crescimento da adoção do RPKI.Prefix hijacking is a problem we currently face on the internet that can lead to the DoS attack or steal information. There are several tools to protect against this type of attack, the RPKI being the most promising, where digital certificates are created to authorize an ASN to announce a certain prefix, and Brazil is adopting this solution. In this work we analyze the growth of the implementation of RPKI in this first year of adoption in Brazil. We also correlated information that shows that training to use this tool has significantly boosted the growth in the adoption of RPKI