This file was created by the TYPO3 extension bib --- Timezone: CEST Creation date: 2024-04-18 Creation time: 21-00-44 --- Number of references 8 inproceedings 2020_delacadena_trafficsliver TrafficSliver: Fighting Website Fingerprinting Attacks with Traffic Splitting 2020 11 12 1971-1985 Website fingerprinting (WFP) aims to infer information about the content of encrypted and anonymized connections by observing patterns of data flows based on the size and direction of packets. By collecting traffic traces at a malicious Tor entry node — one of the weakest adversaries in the attacker model of Tor — a passive eavesdropper can leverage the captured meta-data to reveal the websites visited by a Tor user. As recently shown, WFP is significantly more effective and realistic than assumed. Concurrently, former WFP defenses are either infeasible for deployment in real-world settings or defend against specific WFP attacks only. To limit the exposure of Tor users to WFP, we propose novel lightweight WFP defenses, TrafficSliver, which successfully counter today’s WFP classifiers with reasonable bandwidth and latency overheads and, thus, make them attractive candidates for adoption in Tor. Through user-controlled splitting of traffic over multiple Tor entry nodes, TrafficSliver limits the data a single entry node can observe and distorts repeatable traffic patterns exploited by WFP attacks. We first propose a network-layer defense, in which we apply the concept of multipathing entirely within the Tor network. We show that our network-layer defense reduces the accuracy from more than 98% to less than 16% for all state-of-the-art WFP attacks without adding any artificial delays or dummy traffic. We further suggest an elegant client-side application-layer defense, which is independent of the underlying anonymization network. By sending single HTTP requests for different web objects over distinct Tor entry nodes, our application-layer defense reduces the detection rate of WFP classifiers by almost 50 percentage points. Although it offers lower protection than our network-layer defense, it provides a security boost at the cost of a very low implementation overhead and is fully compatible with today’s Tor network. Traffic Analysis; Website Fingerprinting; Privacy; Anonymous Communication; Onion Routing; Web Privacy https://www.comsys.rwth-aachen.de/fileadmin/papers/2020/2020-delacadena-trafficsliver.pdf https://github.com/TrafficSliver ACM Proceedings of the 27th ACM SIGSAC Conference on Computer and Communications Security (CCS '20), November 9-13, 2020, Orlando, FL, USA Virtual Event, USA November 9-13, 2020 978-1-4503-7089-9/20/11 10.1145/3372297.3423351 1 WladimirDe la Cadena AsyaMitseva JensHiller JanPennekamp SebastianReuter JulianFilter KlausWehrle ThomasEngel AndriyPanchenko inproceedings 2020_matzutt_anonboot Utilizing Public Blockchains for the Sybil-Resistant Bootstrapping of Distributed Anonymity Services 2020 10 7 531-542 Distributed anonymity services, such as onion routing networks or cryptocurrency tumblers, promise privacy protection without trusted third parties. While the security of these services is often well-researched, security implications of their required bootstrapping processes are usually neglected: Users either jointly conduct the anonymization themselves, or they need to rely on a set of non-colluding privacy peers. However, the typically small number of privacy peers enable single adversaries to mimic distributed services. We thus present AnonBoot, a Sybil-resistant medium to securely bootstrap distributed anonymity services via public blockchains. AnonBoot enforces that peers periodically create a small proof of work to refresh their eligibility for providing secure anonymity services. A pseudo-random, locally replicable bootstrapping process using on-chain entropy then prevents biasing the election of eligible peers. Our evaluation using Bitcoin as AnonBoot's underlying blockchain shows its feasibility to maintain a trustworthy repository of 1000 peers with only a small storage footprint while supporting arbitrarily large user bases on top of most blockchains. anonymization; bootstrapping; public blockchain; Sybil attack; anonymity network; cryptocurrency tumbler; Bitcoin; Tor impact_digital; digital_campus https://www.comsys.rwth-aachen.de/fileadmin/papers/2020/2020-matzutt-anonboot.pdf ACM Proceedings of the 15th ACM ASIA Conference on Computer and Communications Security (ASIACCS '20), October 5-9, 2020, Taipei, Taiwan Taipei, Taiwan ASIACCS 2020 October 5-9, 2020 978-1-4503-6750-9/20/10 10.1145/3320269.3384729 1 RomanMatzutt JanPennekamp ErikBuchholz KlausWehrle inproceedings 2020_pennekamp_supply_chain_sensing Secure End-to-End Sensing in Supply Chains 2020 7 1 Trust along digitalized supply chains is challenged by the aspect that monitoring equipment may not be trustworthy or unreliable as respective measurements originate from potentially untrusted parties. To allow for dynamic relationships along supply chains, we propose a blockchain-backed supply chain monitoring architecture relying on trusted hardware. Our design provides a notion of secure end-to-end sensing of interactions even when originating from untrusted surroundings. Due to attested checkpointing, we can identify misinformation early on and reliably pinpoint the origin. A blockchain enables long-term verifiability for all (now trustworthy) IoT data within our system even if issues are detected only after the fact. Our feasibility study and cost analysis further show that our design is indeed deployable in and applicable to today's supply chain settings. supply chain; trusted computing; trusted execution; blockchain; Internet of Production; condition monitoring internet-of-production https://comsys.rwth-aachen.de/fileadmin/papers/2020/2020-pennekamp-supply-chain-sensing.pdf IEEE Proceedings of the 5th International Workshop on Cyber-Physical Systems Security (CPS-Sec '20), co-located with the 8th IEEE Conference on Communications and Network Security (CNS '20), June 29-July 1, 2020, Avignon, France Avignon, France June 29-July 1, 2020 978-1-7281-4760-4 10.1109/CNS48642.2020.9162337 1 JanPennekamp FritzAlder RomanMatzutt Jan TobiasMühlberg FrankPiessens KlausWehrle inproceedings 2020_matzutt_coinprune How to Securely Prune Bitcoin’s Blockchain 2020 6 24 298-306 Bitcoin was the first successful decentralized cryptocurrency and remains the most popular of its kind to this day. Despite the benefits of its blockchain, Bitcoin still faces serious scalability issues, most importantly its ever-increasing blockchain size. While alternative designs introduced schemes to periodically create snapshots and thereafter prune older blocks, already-deployed systems such as Bitcoin are often considered incapable of adopting corresponding approaches. In this work, we revise this popular belief and present CoinPrune, a snapshot-based pruning scheme that is fully compatible with Bitcoin. CoinPrune can be deployed through an opt-in velvet fork, i.e., without impeding the established Bitcoin network. By requiring miners to publicly announce and jointly reaffirm recent snapshots on the blockchain, CoinPrune establishes trust into the snapshots' correctness even in the presence of powerful adversaries. Our evaluation shows that CoinPrune reduces the storage requirements of Bitcoin already by two orders of magnitude today, with further relative savings as the blockchain grows. In our experiments, nodes only have to fetch and process 5 GiB instead of 230 GiB of data when joining the network, reducing the synchronization time on powerful devices from currently 5 h to 46 min, with even more savings for less powerful devices. blockchain; block pruning; synchronization; bootstrapping; scalability; velvet fork; Bitcoin mynedata; impact_digital; digital_campus https://comsys.rwth-aachen.de/fileadmin/papers/2020/2020-matzutt-coinprune.pdf https://coinprune.comsys.rwth-aachen.de IEEE Proceedings of the 19th IFIP Networking 2020 Conference (NETWORKING '20), June 22-26, 2020, Paris, France Paris, France NETWORKING 2020 June 22-26, 2020 978-3-903176-28-7 1 RomanMatzutt BenediktKalde JanPennekamp ArthurDrichel MartinHenze KlausWehrle inproceedings 2020_pennekamp_supply_chain_accountability Private Multi-Hop Accountability for Supply Chains 2020 6 7 Today's supply chains are becoming increasingly flexible in nature. While adaptability is vastly increased, these more dynamic associations necessitate more extensive data sharing among different stakeholders while simultaneously overturning previously established levels of trust. Hence, manufacturers' demand to track goods and to investigate root causes of issues across their supply chains becomes more challenging to satisfy within these now untrusted environments. Complementarily, suppliers need to keep any data irrelevant to such routine checks secret to remain competitive. To bridge the needs of contractors and suppliers in increasingly flexible supply chains, we thus propose to establish a privacy-preserving and distributed multi-hop accountability log among the involved stakeholders based on Attribute-based Encryption and backed by a blockchain. Our large-scale feasibility study is motivated by a real-world manufacturing process, i.e., a fine blanking line, and reveals only modest costs for multi-hop tracing and tracking of goods. supply chain; multi-hop tracking and tracing; blockchain; attribute-based encryption; Internet of Production internet-of-production https://comsys.rwth-aachen.de/fileadmin/papers/2020/2020-pennekamp-supply-chain-privacy.pdf IEEE Proceedings of the 2020 IEEE International Conference on Communications Workshops (ICC Workshops '20), 1st Workshop on Blockchain for IoT and Cyber-Physical Systems (BIoTCPS '20), June 7-11, 2020, Dublin, Ireland Dublin, Ireland June 7-11, 2020 978-1-7281-7440-2 2474-9133 10.1109/ICCWorkshops49005.2020.9145100 1 JanPennekamp LennartBader RomanMatzutt PhilippNiemietz DanielTrauth MartinHenze ThomasBergs KlausWehrle inproceedings 2020-mann-ur-weldseamstudy Study on weld seam geometry control for connected gas metal arc welding systems 2020 6 https://www.comsys.rwth-aachen.de/fileadmin/papers/2020/2020-mann-weld-seam-geometry-control.pdf Proceedings of the 2020 Internal Conference on Ubiquitous Robots Internal Conference on Ubiquitous Robots June 22-26, 2020 10.1109/UR49135.2020.9144839 1 SamuelMann RenéGlebke IkeKunze DominikScheurenberg RahulSharma UweReisgen KlausWehrle DirkAbel article 2020_mann_welding_layers Connected, digitalized welding production — Secure, ubiquitous utilization of data across process layers Advanced Structured Materials 2020 4 1 125 101-118 A connected, digitalized welding production unlocks vast and dynamic potentials: from improving state of the art welding to new business models in production. For this reason, offering frameworks, which are capable of addressing multiple layers of applications on the one hand and providing means of data security and privacy for ubiquitous dataflows on the other hand, is an important step to enable the envisioned advances. In this context, welding production has been introduced from the perspective of interlaced process layers connecting information sources across various entities. Each layer has its own distinct challenges from both a process view and a data perspective. Besides, investigating each layer promises to reveal insight into (currently unknown) process interconnections. This approach has been substantiated by methods for data security and privacy to draw a line between secure handling of data and the need of trustworthy dealing with sensitive data among different parties and therefore partners. In conclusion, the welding production has to develop itself from an accumulation of local and isolated data sources towards a secure industrial collaboration in an Internet of Production. Proceedings of the 1st International Conference on Advanced Joining Processes (AJP '19) Welding Production; Industrie 4.0; Internet of Production; Data Security; Data Privacy Internet-of-Production https://www.comsys.rwth-aachen.de/fileadmin/papers/2020/2020-mann-welding-layers.pdf Springer Ponta Delgada, Azores, Portugal October 24-25, 2019 978-981-15-2956-6 1869-8433 10.1007/978-981-15-2957-3_8 1 SamuelMann JanPennekamp TobiasBrockhoff AnahitaFarhang MahsaPourbafrani LukasOster Merih SeranUysal RahulSharma UweReisgen KlausWehrle Wilvan der Aalst inproceedings 2020_matzutt_coralis A Secure and Practical Decentralized Ecosystem for Shareable Education Material 2020 1 7 529-534 Traditionally, the university landscape is highly federated, which hinders potentials for coordinated collaborations. While the lack of a strict hierarchy on the inter-university level is critical for ensuring free research and higher education, this concurrency limits the access to high-quality education materials. Especially regarding resources such as lecture notes or exercise tasks we observe a high susceptibility to redundant work and lacking quality assessment of material created in isolation by individual university institutes. To remedy this situation, in this paper we propose CORALIS, a decentralized marketplace for offering, acquiring, discussing, and improving education resources across university borders. Our design is based on a permissioned blockchain to (a) realize accountable access control via simple on-chain license terms, (b) trace the evolution of encrypted containers accumulating bundles of shareable education resources, and (c) record user comments and ratings for further improving the quality of offered education material. blockchain platform; permissioned blockchain; education material; quality assessment; collaborative work impact_digital https://comsys.rwth-aachen.de/fileadmin/papers/2020/2020-matzutt-coralis.pdf IEEE Proceedings of the 34th International Conference on Information Networking (ICOIN '20), January 7-10, 2020, Barcelona, Spain Barcelona, Spain January 7-10, 2020 978-1-7281-4199-2 10.1109/ICOIN48656.2020.9016478 1 RomanMatzutt JanPennekamp KlausWehrle