Formal Methods for Wireless Systems

I sistemi wireless sono costituiti da dispositivi che comunicano tra loro per mezzo di un canale radio. Questo paradigma di rete presenta molti vantaggi, ma la presenza del canale radio lo rende intrinsecamente vulnerabile. Di conseguenza, in tale ambito la sicurezza rappresenta un tema importante. I meccanismi di sicurezza messi a punto per i sistemi cablati presentano molti limiti quando vengono utilizzati in una rete wireless. I problemi principali derivano dal fatto che essi operano in modo centralizzato e sotto l'ipotesi di un “mondo chiuso”. Pertanto tecniche formali sono necessarie per stabilire una connessione matematicamente rigorosa tra la modellazione e gli obiettivi di sicurezza. Nella presente tesi si applica il formalismo ben noto del "process calculus" per modellare le principali caratteristiche della comunicazione wireless. Il contributo scientifico è essenzialmente teorico. Verrà proposto un primo process calculus per modellare il passaggio del tempo nei sistemi wireless. Verranno dimostrate alcune interessanti proprietà relative al tempo. Inoltre verrà presentata una rigorosa trattazione dei problemi di collisione. Verranno fornite anche “equivalenze comportamentali” (behavioural equivalence) e verranno dimostrate una serie di leggi algebriche. L'usabilità del calcolo verrà mostrata modellando il Carrier Sense Multiple Access, un diffuso protocollo di livello MAC in cui un dispositivo ascolta il canale prima di trasmettere. Verranno poi analizzati alcuni aspetti di sicurezza, in particolare verrà proposto un modello di trust per le reti ad hoc mobili. Tali reti sono costituite da nodi mobili che comunicano senza l’ausilio di altre infrastrutture. Le reti di tale calcolo verranno modellate come sistemi multilivello perché le relazioni di trust associano ai nodi livelli di sicurezza in base al loro comportamento. Tale modello di trust verrà incluso in un process calculus per reti ad hoc che sarà dotato di equivalenze comportamentali a partire dalle quali verrà sviluppata una "teoria osservazionale" (observational theory). Saranno garantiti sia alcune interessanti proprietà relative alla sicurezza, come la safety in presenza di nodi compromessi, sia risultati di non interferenza. Tale calcolo verrà utilizzato per analizzare una versione “sicura” di un algoritmo per il leader election nelle reti ad hoc. Verrà fornita anche una codifica del protocollo di routing per reti ad hoc chiamato endairA. Infine, il calcolo sul trust verrà esteso con aspetti legati al tempo, per spiegare la relazione tra tempo e trust. Infine quest’ultimo calcolo verrà applicato per dare una codifica del protocollo di routing per reti ad hoc chiamato ARAN.Wireless systems consist of wireless devices which communicate with each other by means of a radio frequency channel. This networking paradigm offers much convenience, but because of the use of the wireless medium it is inherently vulnerable to many threats. As a consequence, security represents an important issue. Security mechanisms developed for wired systems present many limitations when used in a wireless context. The main problems stem from the fact that they operate in a centralised manner and under the assumption of a \closed world". Formal techniques are therefore needed to establish a mathematically rigorous connection between modelling and security goals. In the present dissertation we apply the well-known formalism of process calculus to model the features of wireless communication. The scientic contributions are primarily theoretical.We propose a timed process calculus modelling the communication features of wireless systems and enjoying some desirable time properties. The presence of time allows us to reason about communication collisions. We also provide behavioural equivalences and we prove a number of algebraic laws. We illustrate the usability of the calculus to model the Carrier Sense Multiple Access scheme, a widely used MAC level protocol in which a device senses the channel before transmitting. We then focus on security aspects, in particular we propose a trust model for mobile ad hoc networks, composed only of mobile nodes that communicate each other without relying on any base station. We model our networks as multilevel systems because trust relations associate security levels to nodes depending on their behaviour. Then we embody this trust model in a process calculus modelling the features of ad hoc networks. Our calculus is equipped with behavioural equivalences allowing us to develop an observational theory. We ensure safety despite compromised nodes and non interference results. We then use this calculus to analyse a secure version of a leader election algorithm for ad hoc networks. We also provide an encoding of the endairA routing protocol for ad hoc networks. Finally, we extend the trust-based calculus with timing aspects to reason about the relationship between trust and time. We then apply our calculus to formalise the routing protocol ARAN for ad hoc networks

2013 Oklahoma Research Day Full Program

This document contains all abstracts from the 2013 Oklahoma Research Day held at the University of Central Oklahoma

Approaches and Techniques for Fingerprinting and Attributing Probing Activities by Observing Network Telescopes

The explosive growth, complexity, adoption and dynamism of cyberspace over the last decade has radically altered the globe. A plethora of nations have been at the very forefront of this change, fully embracing the opportunities provided by the advancements in science and technology in order to fortify the economy and to increase the productivity of everyday's life. However, the significant dependence on cyberspace has indeed brought new risks that often compromise, exploit and damage invaluable data and systems. Thus, the capability to proactively infer malicious activities is of paramount importance. In this context, generating cyber threat intelligence related to probing or scanning activities render an effective tactic to achieve the latter. In this thesis, we investigate such malicious activities, which are typically the precursors of various amplified, debilitating and disrupting cyber attacks. To achieve this task, we analyze real Internet-scale traffic targeting network telescopes or darknets, which are defined by routable, allocated yet unused Internet Protocol addresses. First, we present a comprehensive survey of the entire probing topic. Specifically, we categorize this topic by elaborating on the nature, strategies and approaches of such probing activities. Additionally, we provide the reader with a classification and an exhaustive review of various techniques that could be employed in such malicious activities. Finally, we depict a taxonomy of the current literature by focusing on distributed probing detection methods. Second, we focus on the problem of fingerprinting probing activities. To this end, we design, develop and validate approaches that can identify such activities targeting enterprise networks as well as those targeting the Internet-space. On one hand, the corporate probing detection approach uniquely exploits the information that could be leaked to the scanner, inferred from the internal network topology, to perform the detection. On the other hand, the more darknet tailored probing fingerprinting approach adopts a statistical approach to not only detect the probing activities but also identify the exact technique that was employed in the such activities. Third, for attribution purposes, we propose a correlation approach that fuses probing activities with malware samples. The approach aims at detecting whether Internet-scale machines are infected or not as well as pinpointing the exact malware type/family, if the machines were found to be compromised. To achieve the intended goals, the proposed approach initially devises a probabilistic model to filter out darknet misconfiguration traffic. Consequently, probing activities are correlated with malware samples by leveraging fuzzy hashing and entropy based techniques. To this end, we also investigate and report a rare Internet-scale probing event by proposing a multifaceted approach that correlates darknet, malware and passive dns traffic. Fourth, we focus on the problem of identifying and attributing large-scale probing campaigns, which render a new era of probing events. These are distinguished from previous probing incidents as (1) the population of the participating bots is several orders of magnitude larger, (2) the target scope is generally the entire Internet Protocol (IP) address space, and (3) the bots adopt well-orchestrated, often botmaster coordinated, stealth scan strategies that maximize targets' coverage while minimizing redundancy and overlap. To this end, we propose and validate three approaches. On one hand, two of the approaches rely on a set of behavioral analytics that aim at scrutinizing the generated traffic by the probing sources. Subsequently, they employ data mining and graph theoretic techniques to systematically cluster the probing sources into well-defined campaigns possessing similar behavioral similarity. The third approach, on the other hand, exploit time series interpolation and prediction to pinpoint orchestrated probing campaigns and to filter out non-coordinated probing flows. We conclude this thesis by highlighting some research gaps that pave the way for future work

BMCC Borough of Manhattan Community College The City University of New York 2011-2014 Bulletin

This is the official college catalog for 2011-2014. It contains course descriptions as well as information on degree programs, college resources and services, admissions, tuition and fees, financial aid, a profile of the college, and rules and regulations

Abstracts on Radio Direction Finding (1899 - 1995)

The files on this record represent the various databases that originally composed the CD-ROM issue of "Abstracts on Radio Direction Finding" database, which is now part of the Dudley Knox Library's Abstracts and Selected Full Text Documents on Radio Direction Finding (1899 - 1995) Collection. (See Calhoun record https://calhoun.nps.edu/handle/10945/57364 for further information on this collection and the bibliography). Due to issues of technological obsolescence preventing current and future audiences from accessing the bibliography, DKL exported and converted into the three files on this record the various databases contained in the CD-ROM. The contents of these files are: 1) RDFA_CompleteBibliography_xls.zip [RDFA_CompleteBibliography.xls: Metadata for the complete bibliography, in Excel 97-2003 Workbook format; RDFA_Glossary.xls: Glossary of terms, in Excel 97-2003 Workbookformat; RDFA_Biographies.xls: Biographies of leading figures, in Excel 97-2003 Workbook format]; 2) RDFA_CompleteBibliography_csv.zip [RDFA_CompleteBibliography.TXT: Metadata for the complete bibliography, in CSV format; RDFA_Glossary.TXT: Glossary of terms, in CSV format; RDFA_Biographies.TXT: Biographies of leading figures, in CSV format]; 3) RDFA_CompleteBibliography.pdf: A human readable display of the bibliographic data, as a means of double-checking any possible deviations due to conversion

Cumulative index to NASA Tech Briefs, 1986-1990, volumes 10-14

Tech Briefs are short announcements of new technology derived from the R&D activities of the National Aeronautics and Space Administration. These briefs emphasize information considered likely to be transferrable across industrial, regional, or disciplinary lines and are issued to encourage commercial application. This cumulative index of Tech Briefs contains abstracts and four indexes (subject, personal author, originating center, and Tech Brief number) and covers the period 1986 to 1990. The abstract section is organized by the following subject categories: electronic components and circuits, electronic systems, physical sciences, materials, computer programs, life sciences, mechanics, machinery, fabrication technology, and mathematics and information sciences

Transplanting education: a case study of the production of 'American-style' doctors in a non-American setting

This thesis examines the transfer of an American pedagogical model to the Arabian Gulf against the wider context of the globalisation of higher education. Weill Cornell Medical College in Qatar is used as a case study to examine how American medical knowledge and professional practice are transmitted to and assimilated by an Arabic social setting. It considers the workings of what is presumed to be a universal pedagogical model by examining how the degree is culturally translated and localised in Qatar. It addresses the question of whether or not the Cornell degree of “Doctor of Medicine” is simply an American product transplanted to the Middle East, or rather a malleable artefact: sought out, manipulated and shaped by the Qataris for their own ends. Medical education necessitates a highly challenging process of acculturation that is amplified for Arabic-educated students who enter the American medical curriculum without many of the values derived from a Western educational system. In addition to language, students from Arabic-medium schools cite dress, familial, cultural and ethical dissonance as issues that had to be negotiated while undertaking the degree. Students enrolled at the American-style medical college currently divide their clinical training between the Gulf and America. The structure of the imported curriculum and biomedical practices generated in the metropole demand that students become bilingually competent in both Arab and American health care systems. The “American way” of doing things, however, does not always translate or conform to cultural mores and standard practice within the Gulf setting. This thesis follows Arab students as they move between the coeducational American academic setting and local health care facilities, examining the ways that the physicians-in-training contextualise, appropriate and reconstruct the medical degree according to their own cultural referential framework. The thesis introduces the language of “transplantation” as a heuristic tool through which the globalisation of higher education might be explored conceptually. It is an ethnography of an emergent educational transplant propagated in a globalised era, which explores novel modes of knowledge transfer, institutional and social arrangements across local and transnational boundaries, changing subjectivities and the generation of new life forms. In a setting in the Islamic world, Weill Cornell Medical College in Qatar provides a strategic site for observing the dynamics of a nation and its people grappling with modernity. Through its production of Americanstyle doctors in a non-American setting, Cornell’s transnational medical school serves as a niche through which to explore the tensions that arise in global models of tertiary education