3,584 research outputs found
On the Security of the Automatic Dependent Surveillance-Broadcast Protocol
Automatic dependent surveillance-broadcast (ADS-B) is the communications
protocol currently being rolled out as part of next generation air
transportation systems. As the heart of modern air traffic control, it will
play an essential role in the protection of two billion passengers per year,
besides being crucial to many other interest groups in aviation. The inherent
lack of security measures in the ADS-B protocol has long been a topic in both
the aviation circles and in the academic community. Due to recently published
proof-of-concept attacks, the topic is becoming ever more pressing, especially
with the deadline for mandatory implementation in most airspaces fast
approaching.
This survey first summarizes the attacks and problems that have been reported
in relation to ADS-B security. Thereafter, it surveys both the theoretical and
practical efforts which have been previously conducted concerning these issues,
including possible countermeasures. In addition, the survey seeks to go beyond
the current state of the art and gives a detailed assessment of security
measures which have been developed more generally for related wireless networks
such as sensor networks and vehicular ad hoc networks, including a taxonomy of
all considered approaches.Comment: Survey, 22 Pages, 21 Figure
A CRS oedometer cell for unsaturated and non-isothermal tests
Research into the thermo-hydro-mechanical (THM) behavior of unsaturated soils and the effect of strain rate on their mechanical responses requires employment of advanced laboratory testing systems and procedures as well as protocols of correcting the measured data in order to account for errors associated with complex test conditions and apparatus calibrations. This paper presents design and calibration of an innovative constant-rate-of-strain (CRS) oedometer cell for characterization of the THM behavior of soils under combined non-isothermal and unsaturated conditions. The advanced oedometer cell enables for simultaneous control of temperature, suction, and stress state within the soil specimens. Temperatures of 20 to 200° C is applied through a tubular heating element placed at the base of the soil specimen. Suction is controlled using axis-translation technique, and measured using both axis-translation and two high-capacity tensiometers (HCTs) accommodated on the periphery of the specimen. The performance of the new cell is assessed based on a set of tests performed on clay specimens and its merits and advantages are discussed in detail
Lightweight deflectometers for quality assurance in road construction
The use of Lightweight Deflectometers (termed LWDs in Europe, and occasionally
PFWDs in the USA) for construction quality control or material investigation for road construction
has increased worldwide. In the UK the change in pavement foundation design to a
âperformance based approachâ has brought about the use of Lightweight Deflectometers for
field assessment of stiffness modulus. This paper reviews the LWD as a field evaluation tool. It
discusses in some detail the test variables that can influence and affect the field data quality, and
presents brief summaries of recent fieldwork where an LWD has been used as a quality control
tool. The paper concludes both on the LWD usefulness and also its limitations for a variety of
earthwork and road assessment scenarios, and describes a field test protocol for its use on a variety
of materials. The findings demonstrate the flexibility of the LWD but also show that its determination
of âstiffness modulusâ may differ from that of the conventional Falling Weight Deflectometer
(FWD) to a varying extent. The paper provides a useful reference document for
LWD users, consultants, material specifiers, contractors and clients
ERS statement on standardisation of cardiopulmonary exercise testing in chronic lung diseases
The objective of this document was to standardise published cardiopulmonary exercise testing (CPET) protocols for improved interpretation in clinical settings and multicentre research projects. This document: 1) summarises the protocols and procedures used in published studies focusing on incremental CPET in chronic lung conditions; 2) presents standard incremental protocols for CPET on a stationary cycle ergometer and a treadmill; and 3) provides patientsâ perspectives on CPET obtained through an online survey supported by the European Lung Foundation. We systematically reviewed published studies obtained from EMBASE, Medline, Scopus, Web of Science and the Cochrane Library from inception to January 2017. Of 7914 identified studies, 595 studies with 26 523 subjects were included. The literature supports a test protocol with a resting phase lasting at least 3 min, a 3-min unloaded phase, and an 8- to 12-min incremental phase with work rate increased linearly at least every minute, followed by a recovery phase of at least 2â3 min. Patients responding to the survey (n=295) perceived CPET as highly beneficial for their diagnostic assessment and informed the Task Force consensus. Future research should focus on the individualised estimation of optimal work rate increments across different lung diseases, and the collection of robust normative data.The document facilitates standardisation of conducting, reporting and interpreting cardiopulmonary exercise tests in chronic lung diseases for comparison of reference data, multi-centre studies and assessment of interventional efficacy. http://bit.ly/31SXeB
ZETA - Zero-Trust Authentication: Relying on Innate Human Ability, not Technology
Reliable authentication requires the devices and
channels involved in the process to be trustworthy; otherwise
authentication secrets can easily be compromised. Given the
unceasing efforts of attackers worldwide such trustworthiness
is increasingly not a given. A variety of technical solutions,
such as utilising multiple devices/channels and verification
protocols, has the potential to mitigate the threat of untrusted
communications to a certain extent. Yet such technical solutions
make two assumptions: (1) users have access to multiple
devices and (2) attackers will not resort to hacking the human,
using social engineering techniques. In this paper, we propose
and explore the potential of using human-based computation
instead of solely technical solutions to mitigate the threat of
untrusted devices and channels. ZeTA (Zero Trust Authentication
on untrusted channels) has the potential to allow people to
authenticate despite compromised channels or communications
and easily observed usage. Our contributions are threefold:
(1) We propose the ZeTA protocol with a formal definition
and security analysis that utilises semantics and human-based
computation to ameliorate the problem of untrusted devices
and channels. (2) We outline a security analysis to assess
the envisaged performance of the proposed authentication
protocol. (3) We report on a usability study that explores the
viability of relying on human computation in this context
Applications of aerospace technology in the public sector
Current activities of the program to accelerate specific applications of space related technology in major public sector problem areas are summarized for the period 1 June 1971 through 30 November 1971. An overview of NASA technology, technology applications, and supporting activities are presented. Specific technology applications in biomedicine are reported including cancer detection, treatment and research; cardiovascular diseases, diagnosis, and treatment; medical instrumentation; kidney function disorders, treatment, and research; and rehabilitation medicine
Multi-client distributed blind quantum computation with the Qline architecture
Universal blind quantum computing allows users with minimal quantum resources
to delegate a quantum computation to a remote quantum server, while keeping
intrinsically hidden input, algorithm, and outcome. State-of-art experimental
demonstrations of such a protocol have only involved one client. However, an
increasing number of multi-party algorithms, e.g. federated machine learning,
require the collaboration of multiple clients to carry out a given joint
computation. In this work, we propose and experimentally demonstrate a
lightweight multi-client blind quantum computation protocol based on a novel
linear quantum network configuration (Qline). Our protocol originality resides
in three main strengths: scalability, since we eliminate the need for each
client to have its own trusted source or measurement device, low-loss, by
optimizing the orchestration of classical communication between each client and
server through fast classical electronic control, and compatibility with
distributed architectures while remaining intact even against correlated
attacks of server nodes and malicious clients
LiS: Lightweight Signature Schemes for continuous message authentication in cyber-physical systems
Agency for Science, Technology and Research (A*STAR) RIE 202
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