Critical Infrastructures You Can Trust: Where Telecommunications Fits

This paper discusses two NISs: the public telephone network (PTN) and the Internet. Being themselves large and complex NISs, they not only merit study in their own right but can help us to understand some of the technical problems faced by the developers and operators of other NISs. In addition, the high cost of building a global communications infrastructure from the ground up implies that one or both of these two networks is likely to furnish communications services for most other NISs. Therefore, an understanding of the vulnerabilties of the PTN and Internet informs the assessment of the trustworthiness of other NISs. Ideas for improving the trustworthiness of the PTN and Internet are also proposed, both for the short-term (by improved use of existing technologies and procedures) and for the long-term (by identifying some areas where the state-of-the-art is inadequate and research is therefore needed). Finally, some observations are offered about Internet telephony and the use of the Internet for critical infrastructures

FAIR: Forwarding Accountability for Internet Reputability

This paper presents FAIR, a forwarding accountability mechanism that incentivizes ISPs to apply stricter security policies to their customers. The Autonomous System (AS) of the receiver specifies a traffic profile that the sender AS must adhere to. Transit ASes on the path mark packets. In case of traffic profile violations, the marked packets are used as a proof of misbehavior. FAIR introduces low bandwidth overhead and requires no per-packet and no per-flow state for forwarding. We describe integration with IP and demonstrate a software switch running on commodity hardware that can switch packets at a line rate of 120 Gbps, and can forward 140M minimum-sized packets per second, limited by the hardware I/O subsystem. Moreover, this paper proposes a "suspicious bit" for packet headers - an application that builds on top of FAIR's proofs of misbehavior and flags packets to warn other entities in the network.Comment: 16 pages, 12 figure

Assessing and augmenting SCADA cyber security: a survey of techniques

SCADA systems monitor and control critical infrastructures of national importance such as power generation and distribution, water supply, transportation networks, and manufacturing facilities. The pervasiveness, miniaturisations and declining costs of internet connectivity have transformed these systems from strictly isolated to highly interconnected networks. The connectivity provides immense benefits such as reliability, scalability and remote connectivity, but at the same time exposes an otherwise isolated and secure system, to global cyber security threats. This inevitable transformation to highly connected systems thus necessitates effective security safeguards to be in place as any compromise or downtime of SCADA systems can have severe economic, safety and security ramifications. One way to ensure vital asset protection is to adopt a viewpoint similar to an attacker to determine weaknesses and loopholes in defences. Such mind sets help to identify and fix potential breaches before their exploitation. This paper surveys tools and techniques to uncover SCADA system vulnerabilities. A comprehensive review of the selected approaches is provided along with their applicability

A model to study cyber attack mechanics and denial-of-service exploits over the internet\u27s router infrastructure using colored petri nets

The Internet‟s router infrastructure, a scale-free computer network, is vulnerable to targeted denial-of-service (DoS) attacks. Protecting this infrastructure‟s stability is a vital national interest because of the dependence of economic and national security transactions on the Internet. Current defensive countermeasures that rely on monitoring specific router traffic have been shown to be costly, inefficient, impractical, and reactive rather than anticipatory. To address these issues, this research investigation considers a new paradigm that relies on the systemic changes that occur during a cyber attack, rather than individual router traffic anomalies. It has been hypothesized in the literature that systemic knowledge of cyber attack mechanics can be used to infer the existence of an exploit in its formative stages, before severe network degradation occurs. The study described here targeted DoS attacks against large-scale computer networks. To determine whether this new paradigm can be expressed though the study of subtle changes in the physical characteristics of the Internet‟s connectivity environment, this research developed a first of its kind Colored Petri Net (CPN) model of the United States AT&T router connectivity topology. By simulating the systemic affects of a DoS attack over this infrastructure, the objectives of this research were to (1) determine whether it is possible to detect small subtle changes in the connectivity environment of the Internet‟s router connectivity infrastructure that occur during a cyber attack; and (2) if the first premise is valid, to ascertain the feasibility of using these changes as a means for (a) early infrastructure attack detection and (b) router infrastructure protection strategy development against these attacks. Using CPN simulations, this study determined that systemic network changes can be detected in the early stages of a cyber attack. Specifically, this research has provided evidence that using knowledge of the Internet‟s connectivity topology and its physical characteristics to protect the router infrastructure from targeted DoS attacks is feasible. In addition, it is plausible to use these techniques to detect targeted DoS attacks and may lead to new network security tools

On designing large, secure and resilient networked systems

2019 Summer.Includes bibliographical references.Defending large networked systems against rapidly evolving cyber attacks is challenging. This is because of several factors. First, cyber defenders are always fighting an asymmetric warfare: While the attacker needs to find just a single security vulnerability that is unprotected to launch an attack, the defender needs to identify and protect against all possible avenues of attacks to the system. Various types of cost factors, such as, but not limited to, costs related to identifying and installing defenses, costs related to security management, costs related to manpower training and development, costs related to system availability, etc., make this asymmetric warfare even challenging. Second, newer and newer cyber threats are always emerging - the so called zero-day attacks. It is not possible for a cyber defender to defend against an attack for which defenses are yet unknown. In this work, we investigate the problem of designing large and complex networks that are secure and resilient. There are two specific aspects of the problem that we look into. First is the problem of detecting anomalous activities in the network. While this problem has been variously investigated, we address the problem differently. We posit that anomalous activities are the result of mal-actors interacting with non mal-actors, and such anomalous activities are reflected in changes to the topological structure (in a mathematical sense) of the network. We formulate this problem as that of Sybil detection in networks. For our experimentation and hypothesis testing we instantiate the problem as that of Sybil detection in on-line social networks (OSNs). Sybil attacks involve one or more attackers creating and introducing several mal-actors (fake identities in on-line social networks), called Sybils, into a complex network. Depending on the nature of the network system, the goal of the mal-actors can be to unlawfully access data, to forge another user's identity and activity, or to influence and disrupt the normal behavior of the system. The second aspect that we look into is that of building resiliency in a large network that consists of several machines that collectively provide a single service to the outside world. Such networks are particularly vulnerable to Sybil attacks. While our Sybil detection algorithms achieve very high levels of accuracy, they cannot guarantee that all Sybils will be detected. Thus, to protect against such "residual" Sybils (that is, those that remain potentially undetected and continue to attack the network services), we propose a novel Moving Target Defense (MTD) paradigm to build resilient networks. The core idea is that for large enterprise level networks, the survivability of the network's mission is more important than the security of one or more of the servers. We develop protocols to re-locate services from server to server in a random way such that before an attacker has an opportunity to target a specific server and disrupt it’s services, the services will migrate to another non-malicious server. The continuity of the service of the large network is thus sustained. We evaluate the effectiveness of our proposed protocols using theoretical analysis, simulations, and experimentation. For the Sybil detection problem we use both synthetic and real-world data sets. We evaluate the algorithms for accuracy of Sybil detection. For the moving target defense protocols we implement a proof-of-concept in the context of access control as a service, and run several large scale simulations. The proof-of- concept demonstrates the effectiveness of the MTD paradigm. We evaluate the computation and communication complexity of the protocols as we scale up to larger and larger networks

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

Countering DoS Attacks With Stateless Multipath Overlays

Indirection-based overlay networks (IONs) are a promising approach for countering distributed denial of service (DDoS) attacks. Such mechanisms are based on the assumption that attackers will attack a fixed and bounded set of overlay nodes causing service disruption to a small fraction of the users. In addition, attackers cannot eaves-drop on links inside the network or otherwise gain information that can help them focus their attacks on overlay nodes that are critical for specific communication flows. We develop an analytical model and a new class of attacks that considers both simple and advanced adversaries. We show that the impact of these simple attacks on IONs can severely disrupt communications. We propose a stateless spread-spectrum paradigm to create per-packet path diversity between each pair of end-nodes using a modified ION access protocol. Our system protects end-to-end communications from DoS attacks without sacrificing strong client authentication or allowing an attacker with partial connectivity information to repeatedly disrupt communications. Through analysis, we show that an Akamai-sized overlay can withstand attacks involving over 1.3M "zombie" hosts while providing uninterrupted end-to-end connectivity. By using packet replication, the system can resist attacks that render up to 40% of the nodes inoperable. Surprisingly, our experiments on PlanetLab demonstrate that in many cases end-to-end latency decreases when packet replication is used, with a worst-case increase by a factor of 2.5. Similarly, our system imposes less than 15% performance degradation in the end-to-end throughput, even when subjected to a large DDoS attack