250 research outputs found
HoPP: Robust and Resilient Publish-Subscribe for an Information-Centric Internet of Things
This paper revisits NDN deployment in the IoT with a special focus on the
interaction of sensors and actuators. Such scenarios require high
responsiveness and limited control state at the constrained nodes. We argue
that the NDN request-response pattern which prevents data push is vital for IoT
networks. We contribute HoP-and-Pull (HoPP), a robust publish-subscribe scheme
for typical IoT scenarios that targets IoT networks consisting of hundreds of
resource constrained devices at intermittent connectivity. Our approach limits
the FIB tables to a minimum and naturally supports mobility, temporary network
partitioning, data aggregation and near real-time reactivity. We experimentally
evaluate the protocol in a real-world deployment using the IoT-Lab testbed with
varying numbers of constrained devices, each wirelessly interconnected via IEEE
802.15.4 LowPANs. Implementations are built on CCN-lite with RIOT and support
experiments using various single- and multi-hop scenarios
PUF for the Commons: Enhancing Embedded Security on the OS Level
Security is essential for the Internet of Things (IoT). Cryptographic
operations for authentication and encryption commonly rely on random input of
high entropy and secure, tamper-resistant identities, which are difficult to
obtain on constrained embedded devices. In this paper, we design and analyze a
generic integration of physically unclonable functions (PUFs) into the IoT
operating system RIOT that supports about 250 platforms. Our approach leverages
uninitialized SRAM to act as the digital fingerprint for heterogeneous devices.
We ground our design on an extensive study of PUF performance in the wild,
which involves SRAM measurements on more than 700 IoT nodes that aged naturally
in the real-world. We quantify static SRAM bias, as well as the aging effects
of devices and incorporate the results in our system. This work closes a
previously identified gap of missing statistically significant sample sizes for
testing the unpredictability of PUFs. Our experiments on COTS devices of 64 kB
SRAM indicate that secure random seeds derived from the SRAM PUF provide 256
Bits-, and device unique keys provide more than 128 Bits of security. In a
practical security assessment we show that SRAM PUFs resist moderate attack
scenarios, which greatly improves the security of low-end IoT devices.Comment: 18 pages, 12 figures, 3 table
A Guideline on Pseudorandom Number Generation (PRNG) in the IoT
Random numbers are an essential input to many functions on the Internet of
Things (IoT). Common use cases of randomness range from low-level packet
transmission to advanced algorithms of artificial intelligence as well as
security and trust, which heavily rely on unpredictable random sources. In the
constrained IoT, though, unpredictable random sources are a challenging desire
due to limited resources, deterministic real-time operations, and frequent lack
of a user interface.
In this paper, we revisit the generation of randomness from the perspective
of an IoT operating system (OS) that needs to support general purpose or
crypto-secure random numbers. We analyse the potential attack surface, derive
common requirements, and discuss the potentials and shortcomings of current IoT
OSs. A systematic evaluation of current IoT hardware components and popular
software generators based on well-established test suits and on experiments for
measuring performance give rise to a set of clear recommendations on how to
build such a random subsystem and which generators to use.Comment: 43 pages, 11 figures, 11 table
Quantum molecular dynamics simulations for the nonmetal-to-metal transition in fluid helium
We have performed quantum molecular dynamics simulations for dense helium to
study the nonmetal-to-metal transition at high pressures. We present new
results for the equation of state and the Hugoniot curve in the warm dense
matter region. The optical conductivity is calculated via the Kubo-Greenwood
formula from which the dc conductivity is derived. The nonmetal-to-metal
transition is identified at about 1 g/ccm. We compare with experimental results
as well as with other theoretical approaches, especially with predictions of
chemical models.Comment: 4 pages, 5 figure
Security for the Industrial IoT: The Case for Information-Centric Networking
Industrial production plants traditionally include sensors for monitoring or
documenting processes, and actuators for enabling corrective actions in cases
of misconfigurations, failures, or dangerous events. With the advent of the
IoT, embedded controllers link these `things' to local networks that often are
of low power wireless kind, and are interconnected via gateways to some cloud
from the global Internet. Inter-networked sensors and actuators in the
industrial IoT form a critical subsystem while frequently operating under harsh
conditions. It is currently under debate how to approach inter-networking of
critical industrial components in a safe and secure manner.
In this paper, we analyze the potentials of ICN for providing a secure and
robust networking solution for constrained controllers in industrial safety
systems. We showcase hazardous gas sensing in widespread industrial
environments, such as refineries, and compare with IP-based approaches such as
CoAP and MQTT. Our findings indicate that the content-centric security model,
as well as enhanced DoS resistance are important arguments for deploying
Information Centric Networking in a safety-critical industrial IoT. Evaluation
of the crypto efforts on the RIOT operating system for content security reveal
its feasibility for common deployment scenarios.Comment: To be published at IEEE WF-IoT 201
Connecting the World of Embedded Mobiles: The RIOT Approach to Ubiquitous Networking for the Internet of Things
The Internet of Things (IoT) is rapidly evolving based on low-power compliant
protocol standards that extend the Internet into the embedded world. Pioneering
implementations have proven it is feasible to inter-network very constrained
devices, but had to rely on peculiar cross-layered designs and offer a
minimalistic set of features. In the long run, however, professional use and
massive deployment of IoT devices require full-featured, cleanly composed, and
flexible network stacks.
This paper introduces the networking architecture that turns RIOT into a
powerful IoT system, to enable low-power wireless scenarios. RIOT networking
offers (i) a modular architecture with generic interfaces for plugging in
drivers, protocols, or entire stacks, (ii) support for multiple heterogeneous
interfaces and stacks that can concurrently operate, and (iii) GNRC, its
cleanly layered, recursively composed default network stack. We contribute an
in-depth analysis of the communication performance and resource efficiency of
RIOT, both on a micro-benchmarking level as well as by comparing IoT
communication across different platforms. Our findings show that, though it is
based on significantly different design trade-offs, the networking subsystem of
RIOT achieves a performance equivalent to that of Contiki and TinyOS, the two
operating systems which pioneered IoT software platforms
Dynamics of distribution and efficacy of different spot-on permethrin formulations in dogs artificially infested with Dermacentor reticulatus
<p>Abstract</p> <p>Background</p> <p>Varying reports concerning the duration and reliability of different permethrin preparations' efficacy can be found in the literature. The aim of this study was to investigate the dynamics of the distribution and efficacy of four different spot-on formulations with permethrin as the active ingredient formulated with different solvents. To examine the influence of these solvents on the speed of distribution and the acaricidal activity of permethrin in the coat, an <it>in vivo </it>study under laboratory conditions was performed. Six dogs per test period were treated with the recommended dose and 1, 14 and 28 days after treatment dogs were infested with <it>Dermacentor reticulatus </it>ticks: a) on the back, near the application site, and b) on the hind leg, the greatest possible distance from the application site. Efficacies were determined 6 hours after tick infestation to examine the repellent effect and the speed of kill of the products which plays an important role in the context of tick transmitted diseases.</p> <p>Results</p> <p>After six hours of exposure, a significant acaricidal efficacy (p < 0.001) could be observed in all treated groups over the whole duration of the study, regardless of which product was used. While the arithmetic mean of attached ticks was < 3 on Day 1, numbers increased over the course of the study to a mean of > 9 on Day 28. However, most of these ticks were dead even 28 days after treatment, as the mean of live attached ticks was still < 2. Significant differences could neither be found between the different permethrin spot-on formulations, nor between the two parts of the body (p > 0.05).</p> <p>Conclusions</p> <p>All products were able to kill ticks within six hours following infestation from Day 1 to Day 28 after treatment. Additionally, no significant difference between the tick numbers on the back and the hind leg could be found at any time, which implies a homogenous distribution of permethrin over the body. The efficacy of all four products was comparable during the whole study period, showing that the different solvents do not significantly affect the dynamics of distribution.</p
Delay-Tolerant ICN and Its Application to LoRa
Connecting long-range wireless networks to the Internet imposes challenges
due to vastly longer round-trip-times (RTTs). In this paper, we present an ICN
protocol framework that enables robust and efficient delay-tolerant
communication to edge networks. Our approach provides ICN-idiomatic
communication between networks with vastly different RTTs. We applied this
framework to LoRa, enabling end-to-end consumer-to-LoRa-producer interaction
over an ICN-Internet and asynchronous data production in the LoRa edge. Instead
of using LoRaWAN, we implemented an IEEE 802.15.4e DSME MAC layer on top of the
LoRa PHY and ICN protocol mechanisms in RIOT OS. Executed on off-the-shelf IoT
hardware, we provide a comparative evaluation for basic NDN-style ICN [60],
RICE [31]-like pulling, and reflexive forwarding [46]. This is the first
practical evaluation of ICN over LoRa using a reliable MAC. Our results show
that periodic polling in NDN works inefficiently when facing long and differing
RTTs. RICE reduces polling overhead and exploits gateway knowledge, without
violating ICN principles. Reflexive forwarding reflects sporadic data
generation naturally. Combined with a local data push, it operates efficiently
and enables lifetimes of >1 year for battery powered LoRa-ICN nodes.Comment: 12 pages, 7 figures, 2 table
Ageing Analysis of Embedded SRAM on a Large-Scale Testbed Using Machine Learning
Ageing detection and failure prediction are essential in many Internet of
Things (IoT) deployments, which operate huge quantities of embedded devices
unattended in the field for years. In this paper, we present a large-scale
empirical analysis of natural SRAM wear-out using 154 boards from a
general-purpose testbed. Starting from SRAM initialization bias, which each
node can easily collect at startup, we apply various metrics for feature
extraction and experiment with common machine learning methods to predict the
age of operation for this node. Our findings indicate that even though ageing
impacts are subtle, our indicators can well estimate usage times with an
score of 0.77 and a mean error of 24% using regressors, and with an F1 score
above 0.6 for classifiers applying a six-months resolution
Cyclin-Dependent Kinase 5 (CDK5)-Mediated Phosphorylation of Upstream Stimulatory Factor 2 (USF2) Contributes to Carcinogenesis
The transcription factor USF2 is supposed to have an important role in tumor development. However, the regulatory mechanisms contributing to the function of USF2 are largely unknown. Cyclin-dependent kinase 5 (CDK5) seems to be of importance since high levels of CDK5 were found in different cancers associated with high USF2 expression. Here, we identified USF2 as a phosphorylation target of CDK5. USF2 is phosphorylated by CDK5 at two serine residues, serine 155 and serine 222. Further, phosphorylation of USF2 at these residues was shown to stabilize the protein and to regulate cellular growth and migration. Altogether, these results delineate the importance of the CDK5-USF2 interplay in cancer cells
- …