17 research outputs found

    Countering DoS Attacks With Stateless Multipath Overlays

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    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

    Distributed Algorithms for Secure Multipath Routing in Attack-Resistant Networks

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    Smart Grids: A Comprehensive Survey of Challenges, Industry Applications, and Future Trends

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    With the increased energy demands of the 21st century, there is a clear need for developing a more sustainable method of energy generation, distribution, and transmission. The popularity of Smart Grid continues to grow as it presents its benefits, including interconnectivity, improved efficiency, the ability to integrate renewable energy sources, and many more. However, it is not without its challenges. This survey aims to provide an introductory background of smart grids, detail some of the main aspects and current challenges, and review the most recent papers and proposed solutions. It will also highlight the current state of implementation of the smart grid by describing various prototypes, as well as various countries and continents implementation plans and projects.Comment: Paper has been submitted for review to the journal Energy Reports (January 23, 2024). 58 pages, 7 figures, 7 table

    BloomCasting for publish/subscribe networks

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    Publish/subscribe has been proposed as a way of addressing information as the primary named entity in the network. In this thesis, we develop and explore a network architecture based on publish/subscribe primitives, based on our work on PSIRP project. Our work is divided into two areas: rendezvous and Bloomcasting, i.e. fast Bloom filter-based forwarding architecture for source-specific multicast. Taken together these are combined as a publish/subscribe architecture, where publisher and subscriber matching is done by the rendezvous and Bloom filter-based forwarding fabric is used for multicasting the published content. Our work on the inter-domain rendezvous shows that a combination of policy routing at edges and an overlay based on hierarchical distributed hash tables can overcome problems related to incremental deployment while keeping the stretch of queries small and that it can solve some policy related problems that arise from using distributed hash tables in inter-domain setting. Bloom filters can cause false positives. We show that false positives can cause network anomalies, when Bloom filters are used for packet forwarding. We found three such anomalies: packet storms, packet loops, and flow duplication. They can severely disrupt the network infrastructure and be used for denial-of-service attacks against the network or target services. These security and reliability problems can be solved by using the combination of three techniques. Cryptographically computed edge pair-labels ensure that an attacker cannot construct Bloom filter-based path identifiers for chosen path. Varying the Bloom filter parameters locally at each router prevents packet storms and using bit permutations on the Bloom filter locally at each router prevent accidental and malicious loops and flow duplications.Yksi Internetin puutteista on se, ettei ole mitään kaikille sovelluksille yhteistä tapaa nimetä informaatiota. Julkaisija/tilaaja-malli on yksi ehdotus, jolla Internet-arkkitehtuuria voisi muuttaa tämän puutteen korvaamiseksi. Väitöskirjassani kehitän julkaisija/tilaaja-malliin pohjautuvan verkkoarkkitehtuurin, joka pohjautuu työlleni PSRIP-projektissa. Arkkitehtuuri koostuu kohtaamisjärjestelmästä, joka yhdistää julkaisijat ja tilaajat, ja Bloom-suodattimiin pohjautuvasta monen vastaanottajan viestintäkanavasta, jolla julkaistu sisältö toimitetaan tilaajille. Internetin kattavalla kohtaamisjärjestelmällä on korkeat vaatimukset. Tutkin kahta erilaista menetelmää: paikallisiin reitityspolitiikoihin pohjautuvaa järjestelmää ja toinen hajautettuihin hajautustauluihin pohjautuvaa järjestelmää. Ensimmäisen haasteena on skaalautuvuus erityisesti silloin, kun kaikki Internetin verkot eivät osallistu järjestelmän ylläpitoon. Jälkimmäinen on ongelmallinen, sillä siihen pohjautuvat järjestelmät eivät voi taata, mitä reittiä julkaisu ja tilaus -viestit kulkevat järjestelmässä. Näin viesti saattaa kulkea myös julkaisijan tai tilaajan kilpailijan verkon kautta. Ehdotan väitöskirjassani menetelmää, joka yhdistää reunoilla politiikkaan pohjautuvan julkaisu/tilaaja reitityksen ja verkon keskellä yhdistää nämä erilliset saarekkeet hierarkista hajautettua hajautustaulua hyödyntäen. Julkaisujen toimittamiseen tilaajille käytän Bloom-suodattimiin pohjautuvaa järjestelmää. Osoitan väitöskirjassani, että Bloom-suodattimien käyttö pakettien reitittämiseen voi aiheuttaa verkossa merkittäviä vikatilanteita, esimerkiksi pakettiräjähdyksen, silmukan, tai samaan vuohon kuuluvien pakettien moninkertaistumisen. Nämä ongelmat aiheuttavat verkolle turvallisuus- ja luotettavuusongelmia, jotka voidaan ratkaista kolmen tekniikan yhdistelmällä. Ensinnäkin, Bloom-suodattimiin laitettavat polun osia merkitsevät nimet lasketaan kryptografiaa hyödyntäen, ettei hyökkääjä kykene laskemaan Bloom-suodatinta haluamalleen polulle ilman verkon apua. Toisekseen, reitittimet määrittävät Bloom suodatinparametrit paikallisesti siten, ettei pakkettiräjähdyksiä tapahdu. Kolmannekseen, kukin reititin uudelleen järjestelee Bloom-suodattimen bitit varmistaen, ettei suodatin ole enää sama, jos paketti kulkee esimerkiksi silmukan läpi ja palaa samalle takaisin samalle reitittimelle.

    Understanding and Advancing the Status Quo of DDoS Defense

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    Two decades after the first distributed denial-of-service (DDoS) attack, the Internet remains challenged by DDoS attacks as they evolve. Not only is the scale of attacks larger than ever, but they are also harder to detect and mitigate. Nevertheless, the Internet's fundamental design, based on which machines are free to send traffic to any other machines, remains the same. This thesis reinvestigates the prior DDoS defense solutions to find less studied but critical issues in existing defense solutions. It proposes solutions to improve the input, design, and evaluation of DDoS defense. Specifically, we show why DDoS defense systems need a better view of the Internet's traffic at the autonomous system (AS) level. We use a novel attack to expose the inefficiencies in the existing defense systems. Finally, we reason why a defense solution needs a sound empirical evaluation and provide a framework that mimics real-world networks to facilitate DDoS defense evaluation. This dissertation includes published and unpublished co-authored materials

    Countering DoS Attacks With Stateless Multipath Overlays

    No full text
    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 eavesdrop 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 perpacket 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 endto-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
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