1,107 research outputs found
Consensus Algorithms of Distributed Ledger Technology -- A Comprehensive Analysis
The most essential component of every Distributed Ledger Technology (DLT) is
the Consensus Algorithm (CA), which enables users to reach a consensus in a
decentralized and distributed manner. Numerous CA exist, but their viability
for particular applications varies, making their trade-offs a crucial factor to
consider when implementing DLT in a specific field. This article provided a
comprehensive analysis of the various consensus algorithms used in distributed
ledger technologies (DLT) and blockchain networks. We cover an extensive array
of thirty consensus algorithms. Eleven attributes including hardware
requirements, pre-trust level, tolerance level, and more, were used to generate
a series of comparison tables evaluating these consensus algorithms. In
addition, we discuss DLT classifications, the categories of certain consensus
algorithms, and provide examples of authentication-focused and
data-storage-focused DLTs. In addition, we analyze the pros and cons of
particular consensus algorithms, such as Nominated Proof of Stake (NPoS),
Bonded Proof of Stake (BPoS), and Avalanche. In conclusion, we discuss the
applicability of these consensus algorithms to various Cyber Physical System
(CPS) use cases, including supply chain management, intelligent transportation
systems, and smart healthcare.Comment: 50 pages, 20 figure
Intégration des méthodes formelles dans le développement des RCSFs
In this thesis, we have relied on formal techniques in order to first evaluate WSN protocols and then to propose solutions that meet the requirements of these networks. The thesis contributes to the modelling, analysis, design and evaluation of WSN protocols.
In this context, the thesis begins with a survey on WSN and formal verification techniques. Focusing on the MAC layer, the thesis reviews proposed MAC protocols for WSN as well as their design challenges. The dissertation then proceeds to outline the contributions of this work.
As a first proposal, we develop a stochastic generic model of the 802.11 MAC protocol for an arbitrary network topology and then perform probabilistic evaluation of the protocol using statistical model checking. Considering an alternative power source to operate WSN, energy harvesting, we move to the second proposal where a protocol designed for EH-WSN is modelled and various performance parameters are evaluated. Finally, the thesis explores mobility in WSN and proposes a new MAC protocol, named "Mobility and Energy Harvesting aware Medium Access Control (MEH-MAC)" protocol for dynamic sensor networks powered by ambient energy. The protocol is modelled and verified under several features
A Low-Energy Security Solution for IoT-Based Smart Farms
This work proposes a novel configuration of the Transport Layer Security protocol (TLS),
suitable for low energy Internet of Things (IoT), applications. The motivation behind
the redesign of TLS is energy consumption minimisation and sustainable farming, as
exemplified by an application domain of aquaponic smart farms. The work therefore considers
decentralisation of a formerly centralised security model, with a focus on reducing energy
consumption for battery powered devices. The research presents a four-part investigation
into the security solution, composed of a risk assessment, energy analysis of authentication
and data exchange functions, and finally the design and verification of a novel consensus
authorisation mechanism. The first investigation considered traditional risk-driven threat
assessment, but to include energy reduction, working towards device longevity within a
content-oriented framework. Since the aquaponics environments include limited but specific
data exchanges, a content-oriented approach produced valuable insights into security and
privacy requirements that would later be tested by implementing a variety of mechanisms
available on the ESP32.
The second and third investigations featured the energy analysis of authentication
and data exchange functions respectively, where the results of the risk assessment were
implemented to compare the re-configurations of TLS mechanisms and domain content.
Results concluded that selective confidentiality and persistent secure sessions between paired
devices enabled considerable improvements for energy consumptions, and were a good
reflection of the possibilities suggested by the risk assessment.
The fourth and final investigation proposed a granular authorisation design to increase
the safety of access control that would otherwise be binary in TLS. The motivation was
for damage mitigation from inside attacks or network faults. The approach involved an
automated, hierarchy-based, decentralised network topology to reduce data duplication whilst
still providing robustness beyond the vulnerability of central governance. Formal verification
using model-checking indicated a safe design model, using four automated back-ends.
The research concludes that lower energy IoT solutions for the smart farm application
domain are possible
Changing Priorities. 3rd VIBRArch
In order to warrant a good present and future for people around the planet and to safe the care of the planet itself, research in architecture has to release all its potential. Therefore, the aims of the 3rd Valencia International Biennial of Research in Architecture are:
- To focus on the most relevant needs of humanity and the planet and what architectural research can do for solving them.
- To assess the evolution of architectural research in traditionally matters of interest and the current state of these popular and widespread topics.
- To deepen in the current state and findings of architectural research on subjects akin to post-capitalism and frequently related to equal opportunities and the universal right to personal development and happiness.
- To showcase all kinds of research related to the new and holistic concept of sustainability and to climate emergency.
- To place in the spotlight those ongoing works or available proposals developed by architectural researchers in order to combat the effects of the COVID-19 pandemic.
- To underline the capacity of architectural research to develop resiliency and abilities to adapt itself to changing priorities.
- To highlight architecture's multidisciplinarity as a melting pot of multiple approaches, points of view and expertise.
- To open new perspectives for architectural research by promoting the development of multidisciplinary and inter-university networks and research groups.
For all that, the 3rd Valencia International Biennial of Research in Architecture is open not only to architects, but also for any academic, practitioner, professional or student with a determination to develop research in architecture or neighboring fields.Cabrera Fausto, I. (2023). Changing Priorities. 3rd VIBRArch. Editorial Universitat Politècnica de València. https://doi.org/10.4995/VIBRArch2022.2022.1686
- …