JA-trie: Entropy-based packet classification

Any improvement in packet classification performance is crucial to ensure Internet functions continue to track the ever-increasing link capacities. Packet classification is the foundation of many Internet functions: from fundamental packet-forwarding to advanced features such as Quality of Service en-forcement, monitoring and security functions. This work proposes a novel trie-based classification algorithm, named Jump-Ahead Trie (JA-trie), utilizing an entropy-based pre-processing phase and a novel approach to wildcard matching. Through extensive experimental tests, we demonstrate that our proposed algorithm is able to outperform a range of state-of-the-art classification algorithms.This work was jointly supported by the EPSRC INTERNET Project EP/H040536/1, by the National Science Foundation under Grant No. CNS-0855268, and by the MIUR project GreenNet (FIRB 2010).This is the accepted manuscript. The final version is available at http://ieeexplore.ieee.org/xpl/articleDetails.jsp?arnumber=6900878

Detecting Anomalous Microflows in IoT Volumetric Attacks via Dynamic Monitoring of MUD Activity

IoT networks are increasingly becoming target of sophisticated new cyber-attacks. Anomaly-based detection methods are promising in finding new attacks, but there are certain practical challenges like false-positive alarms, hard to explain, and difficult to scale cost-effectively. The IETF recent standard called Manufacturer Usage Description (MUD) seems promising to limit the attack surface on IoT devices by formally specifying their intended network behavior. In this paper, we use SDN to enforce and monitor the expected behaviors of each IoT device, and train one-class classifier models to detect volumetric attacks. Our specific contributions are fourfold. (1) We develop a multi-level inferencing model to dynamically detect anomalous patterns in network activity of MUD-compliant traffic flows via SDN telemetry, followed by packet inspection of anomalous flows. This provides enhanced fine-grained visibility into distributed and direct attacks, allowing us to precisely isolate volumetric attacks with microflow (5-tuple) resolution. (2) We collect traffic traces (benign and a variety of volumetric attacks) from network behavior of IoT devices in our lab, generate labeled datasets, and make them available to the public. (3) We prototype a full working system (modules are released as open-source), demonstrates its efficacy in detecting volumetric attacks on several consumer IoT devices with high accuracy while maintaining low false positives, and provides insights into cost and performance of our system. (4) We demonstrate how our models scale in environments with a large number of connected IoTs (with datasets collected from a network of IP cameras in our university campus) by considering various training strategies (per device unit versus per device type), and balancing the accuracy of prediction against the cost of models in terms of size and training time.Comment: 18 pages, 13 figure

High-Performance Packet Processing Engines Using Set-Associative Memory Architectures

The emergence of new optical transmission technologies has led to ultra-high Giga bits per second (Gbps) link speeds. In addition, the switch from 32-bit long IPv4 addresses to the 128-bit long IPv6 addresses is currently progressing. Both factors make it hard for new Internet routers and firewalls to keep up with wire-speed packet-processing. By packet-processing we mean three applications: packet forwarding, packet classification and deep packet inspection. In packet forwarding (PF), the router has to match the incoming packet's IP address against the forwarding table. It then directs each packet to its next hop toward its final destination. A packet classification (PC) engine examines a packet header by matching it against a database of rules, or filters, to obtain the best matching rule. Rules are associated with either an ``action'' (e.g., firewall) or a ``flow ID'' (e.g., quality of service or QoS). The last application is deep packet inspection (DPI) where the firewall has to inspect the actual packet payload for malware or network attacks. In this case, the payload is scanned against a database of rules, where each rule is either a plain text string or a regular expression. In this thesis, we introduce a family of hardware solutions that combine the above requirements. These solutions rely on a set-associative memory architecture that is called CA-RAM (Content Addressable-Random Access Memory). CA-RAM is a hardware implementation of hash tables with the property that each bucket of a hash table can be searched in one memory cycle. However, the classic hashing downsides have to be dealt with, such as collisions that lead to overflow and worst-case memory access time. The two standard solutions to the overflow problem are either to use some predefined probing (e.g., linear or quadratic) or to use multiple hash functions. We present new hash schemes that extend both aforementioned solutions to tackle the overflow problem efficiently. We show by experimenting with real IP lookup tables, synthetic packet classification rule sets and real DPI databases that our schemes outperform other previously proposed schemes

DETECTION OF EFFICIENT PACKET CLASSIFICATION STRATEGY FOR IMPROVISATION OF PERFORMANCE

Several efforts were made in the existing solutions to identify a successful packet classification solution. A variety of decision-tree-based packet classification algorithms were analysed in our works. Earlier decision tree algorithms chooses field as well as number of cuts based on a nearby optimized decision, which compromises search speed as well as memory requirement. Algorithms of decision tree make possible maximum priority match and multi-match packet classification. New applications of networks have demanded a multi-match packet classification in which the entire matching results along with highest-priority matching rule have to be returned and it is essential to discover competent algorithms to resolve classification problems. A new resourceful packet classification algorithm was introduced in our work named as boundary cutting. Mainly conventional applications of packet classification necessitate the maximum priority matching. The algorithm that was introduced has two principal advantages. Boundary cutting of projected algorithm is more effectual than that of earlier algorithms as it is based on rule boundaries to a certain extent than permanent intervals thus, amount of necessary memory is considerably reduced. Although boundary cutting loses indexing capability at internal nodes binary search recommend better-quality search performance

Toward Open and Programmable Wireless Network Edge

Increasingly, the last hop connecting users to their enterprise and home networks is wireless. Wireless is becoming ubiquitous not only in homes and enterprises but in public venues such as coffee shops, hospitals, and airports. However, most of the publicly and privately available wireless networks are proprietary and closed in operation. Also, there is little effort from industries to move forward on a path to greater openness for the requirement of innovation. Therefore, we believe it is the domain of university researchers to enable innovation through openness. In this thesis work, we introduce and defines the importance of open framework in addressing the complexity of the wireless network. The Software Defined Network (SDN) framework has emerged as a popular solution for the data center network. However, the promise of the SDN framework is to make the network open, flexible and programmable. In order to deliver on the promise, SDN must work for all users and across all networks, both wired and wireless. Therefore, we proposed to create new modules and APIs to extend the standard SDN framework all the way to the end-devices (i.e., mobile devices, APs). Thus, we want to provide an extensible and programmable abstraction of the wireless network as part of the current SDN-based solution. In this thesis work, we design and develop a framework, weSDN (wireless extension of SDN), that extends the SDN control capability all the way to the end devices to support client-network interaction capabilities and new services. weSDN enables the control-plane of wireless networks to be extended to mobile devices and allows for top-level decisions to be made from an SDN controller with knowledge of the network as a whole, rather than device centric configurations. In addition, weSDN easily obtains user application information, as well as the ability to monitor and control application flows dynamically. Based on the weSDN framework, we demonstrate new services such as application-aware traffic management, WLAN virtualization, and security management

Some Worlds of Quantum Theory

This paper assesses the Everettian approach to the measurement problem, especially the version of that approach advocated by Simon Saunders and David Wallace. I emphasise conceptual, indeed metaphysical, aspects rather than technical ones; but I include an introductory exposition of decoherence. In particular, I discuss whether -- as these authors maintain -- it is acceptable to have no precise definition of 'branch' (in the Everettian kind of sense).Comment: 42 pages, no figures: a pdf file. A version of this paper will appear in a CTNS/Vatican Observatory volume on Quantum Theory and Divine Action, ed. Robert Russell et a

Improving the Policy Specification for Practical Access Control Systems

Access control systems play a crucial role in protecting the security of information systems by ensuring that only authorized users are granted access to sensitive resources, and the protection is only as good as the access control policies. For enabling a security administrator to express her desired policy conveniently, it is paramount that a policy specification is expressive, comprehensible, and free of inconsistencies. In this dissertation, we study the policy specifications for three practical access control systems (i.e., obligation systems, firewalls, and Security-Enhanced Linux in Android) and improve their expressiveness, comprehensibility, and consistency. First, we improve the expressiveness of obligation policies for handling different types of obligations. We propose a language for specifying obligations as well as an architecture for handling access control policies with these obligations, by extending XACML (i.e., the de facto standard for specifying access control policies). We also implement our design into a prototype system named ExtXACML to handle various obligations. Second, we improve the comprehensibility of firewall policies enabling administrators to better understand and manage the policies. We introduce the tri-modularized design of firewall policies for elevating them from monolithic to modular. To support legacy firewall policies, we also define a five-step process and present algorithms for converting them into their modularized form. Finally, we improve the consistency of Security-Enhanced Linux in Android (SEAndroid) policies for reducing the attack surface in Android systems. We propose a systematic approach as well as a semiautomatic tool for uncovering three classes of policy misconfigurations. We also analyze SEAndroid policies from four Android versions and seven Android phone vendors, and in all of them we observe examples of potential policy misconfigurations