20,957 research outputs found
Exploring Deployment Strategies for the Tor Network
In response to upcoming performance and security challenges of anonymity networks like Tor, it will be of crucial importance to be able to develop and deploy performance improvements and state-of-the-art countermeasures. In this paper, we therefore explore different deployment strategies and review their applicability, impact, and risks to the Tor network. In a simulation-based evaluation, which leverages historical data of Tor, we show that the deployment strategies can practically be applied to realize significant protocol changes in Tor. Our results, however, also indicate that during the transitional phase a certain degradation of anonymity is unavoidable
Exploring Deployment Strategies for the Tor Network [Extended Version]
In response to upcoming performance and security challenges of anonymity networks like Tor, it will be of crucial importance to be able to develop and deploy performance improvements and state-of-the-art countermeasures. In this paper, we therefore explore different deployment strategies and review their applicability to the Tor network. In particular, we consider flag day, dual stack, translation, and tunneling strategies and discuss their impact on the network, as well as common risks associated with each of them. In a simulation based evaluation, which stems on historical data of Tor, we show that they can practically be applied to realize significant protocol changes in Tor. However, our results also indicate that during the transitional phase a certain degradation of anonymity is unavoidable with current viable deployment strategies
Creating Tailored and Adaptive Network Services with the Open Orchestration C-RAN Framework
Next generation wireless communications networks will leverage
software-defined radio and networking technologies, combined with cloud and fog
computing. A pool of resources can then be dynamically allocated to create
personalized network services (NSs). The enabling technologies are abstraction,
virtualization and consolidation of resources, automatization of processes, and
programmatic provisioning and orchestration. ETSI's network functions
virtualization (NFV) management and orchestration (MANO) framework provides the
architecture and specifications of the management layers. We introduce OOCRAN,
an open-source software framework and testbed that extends existing NFV
management solutions by incorporating the radio communications layers. This
paper presents OOCRAN and illustrates how it monitors and manages the pool of
resources for creating tailored NSs. OOCRAN can automate NS reconfiguration,
but also facilitates user control. We demonstrate the dynamic deployment of
cellular NSs and discuss the challenges of dynamically creating and managing
tailored NSs on shared infrastructure.Comment: IEEE 5G World Forum 201
POTs: Protective Optimization Technologies
Algorithmic fairness aims to address the economic, moral, social, and
political impact that digital systems have on populations through solutions
that can be applied by service providers. Fairness frameworks do so, in part,
by mapping these problems to a narrow definition and assuming the service
providers can be trusted to deploy countermeasures. Not surprisingly, these
decisions limit fairness frameworks' ability to capture a variety of harms
caused by systems.
We characterize fairness limitations using concepts from requirements
engineering and from social sciences. We show that the focus on algorithms'
inputs and outputs misses harms that arise from systems interacting with the
world; that the focus on bias and discrimination omits broader harms on
populations and their environments; and that relying on service providers
excludes scenarios where they are not cooperative or intentionally adversarial.
We propose Protective Optimization Technologies (POTs). POTs provide means
for affected parties to address the negative impacts of systems in the
environment, expanding avenues for political contestation. POTs intervene from
outside the system, do not require service providers to cooperate, and can
serve to correct, shift, or expose harms that systems impose on populations and
their environments. We illustrate the potential and limitations of POTs in two
case studies: countering road congestion caused by traffic-beating
applications, and recalibrating credit scoring for loan applicants.Comment: Appears in Conference on Fairness, Accountability, and Transparency
(FAT* 2020). Bogdan Kulynych and Rebekah Overdorf contributed equally to this
work. Version v1/v2 by Seda G\"urses, Rebekah Overdorf, and Ero Balsa was
presented at HotPETS 2018 and at PiMLAI 201
Systematizing Decentralization and Privacy: Lessons from 15 Years of Research and Deployments
Decentralized systems are a subset of distributed systems where multiple
authorities control different components and no authority is fully trusted by
all. This implies that any component in a decentralized system is potentially
adversarial. We revise fifteen years of research on decentralization and
privacy, and provide an overview of key systems, as well as key insights for
designers of future systems. We show that decentralized designs can enhance
privacy, integrity, and availability but also require careful trade-offs in
terms of system complexity, properties provided, and degree of
decentralization. These trade-offs need to be understood and navigated by
designers. We argue that a combination of insights from cryptography,
distributed systems, and mechanism design, aligned with the development of
adequate incentives, are necessary to build scalable and successful
privacy-preserving decentralized systems
Earthquake Early Warning and Beyond: Systems Challenges in Smartphone-based Seismic Network
Earthquake Early Warning (EEW) systems can effectively reduce fatalities,
injuries, and damages caused by earthquakes. Current EEW systems are mostly
based on traditional seismic and geodetic networks, and exist only in a few
countries due to the high cost of installing and maintaining such systems. The
MyShake system takes a different approach and turns people's smartphones into
portable seismic sensors to detect earthquake-like motions. However, to issue
EEW messages with high accuracy and low latency in the real world, we need to
address a number of challenges related to mobile computing. In this paper, we
first summarize our experience building and deploying the MyShake system, then
focus on two key challenges for smartphone-based EEW (sensing heterogeneity and
user/system dynamics) and some preliminary exploration. We also discuss other
challenges and new research directions associated with smartphone-based seismic
network.Comment: 6 pages, conference paper, already accepted at hotmobile 201
HPC Cloud for Scientific and Business Applications: Taxonomy, Vision, and Research Challenges
High Performance Computing (HPC) clouds are becoming an alternative to
on-premise clusters for executing scientific applications and business
analytics services. Most research efforts in HPC cloud aim to understand the
cost-benefit of moving resource-intensive applications from on-premise
environments to public cloud platforms. Industry trends show hybrid
environments are the natural path to get the best of the on-premise and cloud
resources---steady (and sensitive) workloads can run on on-premise resources
and peak demand can leverage remote resources in a pay-as-you-go manner.
Nevertheless, there are plenty of questions to be answered in HPC cloud, which
range from how to extract the best performance of an unknown underlying
platform to what services are essential to make its usage easier. Moreover, the
discussion on the right pricing and contractual models to fit small and large
users is relevant for the sustainability of HPC clouds. This paper brings a
survey and taxonomy of efforts in HPC cloud and a vision on what we believe is
ahead of us, including a set of research challenges that, once tackled, can
help advance businesses and scientific discoveries. This becomes particularly
relevant due to the fast increasing wave of new HPC applications coming from
big data and artificial intelligence.Comment: 29 pages, 5 figures, Published in ACM Computing Surveys (CSUR
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