The Tor network gives anonymity to Internet users by relaying their traffic through the world over a variety of routers. This incurs latency, and this thesis first explores where this latency occurs. Experiments discount the latency induced by routing traffic and computational latency to determine there is a substantial component that is caused by delay in the communication path. We determine that congestion control is causing the delay. Tor multiplexes multiple streams of data over a single TCP connection. This is not a wise use of TCP, and as such results in the unfair application of congestion control. We illustrate an example of this occurrence on a Tor node on the live network and also illustrate how packet dropping and reordering cause interference between the multiplexed streams. Our solution is to use a TCP-over-DTLS (Datagram Transport Layer Security) transport between routers, and give each stream of data its own TCP connection. We give our design for our proposal, and details about its implementation. Finally, we perform experiments on our implemented version to illustrate that our proposal has in fact resolved the multiplexing issues discovered in our system performance analysis. The future work gives a number of steps towards optimizing and improving our work, along with some tangential ideas that were discovered during research. Additionally, the open-source software projects latency_proxy and libspe, which were designed for our purposes but programmed for universal applicability, are discussed.

The Tor network gives anonymity to Internet users by relaying their traffic through the world over a variety of routers. This incurs latency, and this thesis first explores where this latency occurs. Experiments discount the latency induced by routing traffic and computational latency to determine there is a substantial component that is caused by delay in the communication path. We determine that congestion control is causing the delay. Tor multiplexes multiple streams of data over a single TCP connection. This is not a wise use of TCP, and as such results in the unfair application of congestion control. We illustrate an example of this occurrence on a Tor node on the live network and also illustrate how packet dropping and reordering cause interference between the multiplexed streams. Our solution is to use a TCP-over-DTLS (Datagram Transport Layer Security) transport between routers, and give each stream of data its own TCP connection. We give our design for our proposal, and details about its implementation. Finally, we perform experiments on our implemented version to illustrate that our proposal has in fact resolved the multiplexing issues discovered in our system performance analysis. The future work gives a number of steps towards optimizing and improving our work, along with some tangential ideas that were discovered during research. Additionally, the open-source software projects latency_proxy and libspe, which were designed for our purposes but programmed for universal applicability, are discussed.

An ever increasing amount of governments, organisations, and companies employ Internet censorship in order to filter the free flow of information.  These efforts are supported by an equally increasing number of companies focusing on the development of filtering equipment. Only what these entities consider right can pass the filters. This practice constitutes a violation of the Universal Declaration of Human Rights and hampers progress.  This thesis contributes novel techniques to measure and to circumvent Internet censorship. In particular, we 1) analyse how the Great Firewall of China is blocking the Tor network by using active probing techniques as well as side channel measurements, we 2) propose a concept to involve users in the process of censorship analysis, we 3) discuss the aptitude of a globally-deployed network measurement platform for censorship analysis, and we 4) propose a novel circumvention protocol. We attach particular importance to practicality and usability. Most of the techniques proposed in this thesis were implemented and some of them are deployed and used on a daily basis.  We demonstrate that the measurement techniques proposed in this thesis are practical and useful by applying them in order to shed light on previously undocumented cases of Internet censorship. We employed our techniques in three countries and were able to expose previously unknown censorship techniques and cooperation between a corporation and a government for the sake of censorship. We also implemented a circumvention protocol which was subsequently deployed and is used to evade the Great Firewall of China.

The sensitivity of Notch signaling pathway to metabolism has been proposed in several recent studies but it is unclear if the changes in fly diet composition can directly lead to changes in Notch phenotype in vivo. In this work we show that activity of Notch pathway is sensitive to amino acids via the TOR pathway. In addition we will test a candidate protein as a sensor for amino acid level in the fat body of Drosophila melanogaster but also independently in other tissues.

En premier lieu, l'horloge circadienne des mammifères joue un rôle fondamental dans le foie en régulant le métabolisme des acides gras, du glucose et des xénobiotiques. L'altération de ce rythme a été montrée comme menant à diverses pathologies incluant le syndrome métabolique. Il est supposé que l'horloge circadienne régule principalement le métabolisme en régulant l'expression des enzymes hépatiques au niveau transcriptionnel. Nous montrons que l'horloge circadienne contrôle au ssi le métabolisme hépatique en synchronisant un rythme secondaire d'une période de 12 heures caractérisé par l'activation rythmique de la voie IRE1a dans le RE. L'absence d'horloge circadienne perturbe cette horloge secondaire et provoque une dérégulation des enzymes localisées dans le RE. Cela mène à une altération du métabolisme lipidique, résultant en une activation aberrante du facteur de transcription SREBP. Cette altération dans le métabolisme lipidique circadien chez les souris sans horloge pourrait être impliquée dans l'apparition du syndrome métabolique. D'autre part, la croissance cellulaire animale est principalement régulée par la détection des nutriments et est principalement médiée par la voie TOR. Chez la souris, un gène est identifié pour la kinase TOR et son association en complexe avec d'autres protéines permet de discriminer TORC1 et TORC2. TORC1 est la forme majeure sensible à la rapamycine et est le premier médiateur de la détection d'énergie et d'acides aminés pour le contrôle de la croissance. Ce contrôle consiste en la régulation de la traduction par la phosphorylation de S6 Kinase et 4E-BP et le contrôle de la biogenèse des ribosomes. Nous sommes intéressés de montrer si l'horloge circadienne régule la traduction régulée par TOR dans le foie de souris. / In one hand, The mammalian circadian clock plays a fundamental role in the liver by regulating fatty acid, glucose, and xenobiotic metabolism. Impairment of this rhythm has been shown to lead to diverse pathologies, including metabolic syndrome. Currently, it is supposed that the circadian clock regulates metabolism mostly by regulating expression of liver enzymes at the transcriptional level. We show that the circadian clock also controls hepatic metabolism by synchronizing a secondary 12 hr period rhythm characterized by rhythmic activation of the IRE1a pathway in the endoplasmic reticulum. The absence of circadian clock perturbs this secondary clock and provokes deregulation of endoplasmic reticulum localized enzymes. This leads to impaired lipid metabolism, resulting in aberrant activation of the sterol-regulated SREBP transcription factors. The resulting aberrant circadian lipid metabolism in mice devoid of the circadian clock could be inv olved in the appearance of the associated metabolic syndrome.In a second hand, the tissue growth in animals is principally regulated by nutrient sensing and principally by the protein kinase TOR. In mice one gene is identified as TOR kinase and the association of Tor protein associated with 2 different complex of protein (TORC1 and TORC2). TORC1 is the major rapamycin sensitive form and is the primary mediator of energy and amino acid sensing for growth control. This control consists in the regulation of translation through the phosphorylation of S6 Kinase (ribosomal S6 kinase) and 4E-BP (Eif4E binding protein) and the control of ribosome biogenesis. We are interested to show if the circadian clock regulate TOR translation regulation in mice liver.

Dissertação de mestrado integrado conduzida na Universidade de Maryland / Tese de mestrado integrado. Engenharia Química. Universidade do Porto. Faculdade de Engenharia. 2011

Uppsatsen bygger på en analys av en exit-nod i Tor-nätverket i syfte att efterlikna ett tidigare experiment från 2007. Experimentet går ut på att analysera den information som kommer genom nätverket för att leta efter okrypterade lösenord. Experimentet görs i syfte att påvisa de brister som finns i nätverket och i användarnas säkerhetsmedvetande. Arbetet utgår från frågeställningarna: Går det att utvinna känslig information från en exit-nod i Tor-nätverket. -       Går det att utvinna okrypterade lösenord från en exit-nod i nätverket? -       Vilka typer av tjänster tillhör lösenorden som uppkommer i analysen av den insamlade data? För att kunna besvara mina tre frågeställningar har jag valt att göra ett experimentellt arbete för att ta reda på om användarna skickar okrypterade lösenord, och till vilka tjänster lösenorden tillhör. Som referens för min metod användes Dan Egerstads experiment[9] och ShiningLight in Dark Places: Understanding the Tor[11]. Genom att kombinera metoderna i dessa två arbeten uppnådes förljande resultat: 24 okrypterade lösenord på 54,5 GB insamlad data. Statistiskt sett skickas det 1 okrypterat lösenord per 2,1 GB data.

Thesis (M.C.P.)--Massachusetts Institute of Technology, Dept. of Urban Studies and Planning, 2013. / This electronic version was submitted by the student author. The certified thesis is available in the Institute Archives and Special Collections. / Cataloged from student-submitted PDF version of thesis. / Includes bibliographical references (p. 96-98). / Twenty three years after the German Reunification (German: Deutsche Wiedervereinigung), the once divided Berlin is still undergoing a process of recovery from the deep political, social, cultural, and physical divisions of the 20th century. Such divisions seem to have manifested themselves in every corner of the city throughout the course of history, creating a highly politicized environment, and hotly contested spaces decades after conflict ended. One particular area of controversy lies in the center of the city, along the former path of the Berlin Wall. This part of the city was heavily destroyed after the Second World War. Despite some unsuccessful reconstruction efforts after the War, the Berlin Wall passed right through the center of the city, wiping out the few buildings that were left standing, leaving the area completely barren and deserted. This area of the city came to be known as the 'death strip' (German: Todesstreifen), characterized by a long wide empty space, a wall on the west, barbed wire on the east, and occasional checkpoints and military units along the way. Over the last twenty three years, the Senate Department for Urban Development and the Environment (German: Berlin Stadtentwicklung) has sought to restore, preserve, rebuild, and develop large parts of the city, including the former death strip. Its goal has been to physically reconnect fragmented parts the city, by creating spaces that serve as meeting points for former East and West Berliners, in order to reintegrate the city's physical landscape and recreate its cultural identity. One of the Senate's key development projects focused on the Brandenburg Gate, Berlin's iconic landmark, and its surrounding public spaces, for the political, cultural, and historic symbolism they represent to the city. This thesis will first examine the conditions under which the Brandenburg Gate has served as a symbol of unity and division in the city throughout its evolving history. Then, it will discuss the Brandenburg Gate and its surrounding spaces as a network of reinvented traditions, with the Gate serving as passageway to the physical and temporal histories to the city-hence, the Brandenburg Gates. / by Dima Ayyash. / M.C.P.

Tor is a popular anonymity-preserving network, consisting of routers run by volunteers all around the world. It protects Internet users’ privacy by relaying their network traffic through a series of routers, thus concealing the linkage between the sender and the recipient. Despite the advantage of Tor’s anonymizing capabilities, it also brings extra latency, which discourages more users from joining the network. One of the factors that causes the latency lies in Tor’s circuit scheduling algorithm, which allows busy circuits to crowd out bursty circuits. In this work, we propose and implement a more advanced scheduling algorithm which treats circuits differently, based on their recent activity. In this way, bursty circuits such as those used for web browsing can gain higher priority over busy ones such as used for bulk transfer; the performance for most activities over Tor is improved, while minimal overhead is incurred. Our algorithm has been incorporated into the latest build of Tor.

Tor is a popular anonymity-preserving network, consisting of routers run by volunteers all around the world. It protects Internet users’ privacy by relaying their network traffic through a series of routers, thus concealing the linkage between the sender and the recipient. Despite the advantage of Tor’s anonymizing capabilities, it also brings extra latency, which discourages more users from joining the network. One of the factors that causes the latency lies in Tor’s circuit scheduling algorithm, which allows busy circuits to crowd out bursty circuits. In this work, we propose and implement a more advanced scheduling algorithm which treats circuits differently, based on their recent activity. In this way, bursty circuits such as those used for web browsing can gain higher priority over busy ones such as used for bulk transfer; the performance for most activities over Tor is improved, while minimal overhead is incurred. Our algorithm has been incorporated into the latest build of Tor.