When Private Blockchain Meets Deterministic Database

Private blockchain as a replicated transactional system shares many commonalities with distributed database. However, the intimacy between private blockchain and deterministic database has never been studied. In essence, private blockchain and deterministic database both ensure replica consistency by determinism. In this paper, we present a comprehensive analysis to uncover the connections between private blockchain and deterministic database. While private blockchains have started to pursue deterministic transaction executions recently, deterministic databases have already studied deterministic concurrency control protocols for almost a decade. This motivates us to propose Harmony, a novel deterministic concurrency control protocol designed for blockchain use. We use Harmony to build a new relational blockchain, namely HarmonyBC, which features low abort rates, hotspot resiliency, and inter-block parallelism, all of which are especially important to disk-oriented blockchain. Empirical results on Smallbank, YCSB, and TPC-C show that HarmonyBC offers 2.0x to 3.5x throughput better than the state-of-the-art private blockchains

Trends in Development of Databases and Blockchain

This work is about the mutual influence between two technologies: Databases and Blockchain. It addresses two questions: 1. How the database technology has influenced the development of blockchain technology?, and 2. How blockchain technology has influenced the introduction of new functionalities in some modern databases? For the first question, we explain how database technology contributes to blockchain technology by unlocking different features such as ACID (Atomicity, Consistency, Isolation, and Durability) transactional consistency, rich queries, real-time analytics, and low latency. We explain how the CAP (Consistency, Availability, Partition tolerance) theorem known for databases influenced the DCS (Decentralization, Consistency, Scalability) theorem for the blockchain systems. By using an analogous relaxation approach as it was used for the proof of the CAP theorem, we postulate a "DCS-satisfiability conjecture." For the second question, we review different databases that are designed specifically for blockchain and provide most of the blockchain functionality like immutability, privacy, censorship resistance, along with database features.Comment: Accepted in The Second International Workshop on Blockchain Applications and Theory (BAT 2020

Results and achievements of the ALLIANCE Project: New network solutions for 5G and beyond

Leaving the current 4th generation of mobile communications behind, 5G will represent a disruptive paradigm shift integrating 5G Radio Access Networks (RANs), ultra-high-capacity access/metro/core optical networks, and intra-datacentre (DC) network and computational resources into a single converged 5G network infrastructure. The present paper overviews the main achievements obtained in the ALLIANCE project. This project ambitiously aims at architecting a converged 5G-enabled network infrastructure satisfying those needs to effectively realise the envisioned upcoming Digital Society. In particular, we present two networking solutions for 5G and beyond 5G (B5G), such as Software Defined Networking/Network Function Virtualisation (SDN/NFV) on top of an ultra-high-capacity spatially and spectrally flexible all-optical network infrastructure, and the clean-slate Recursive Inter-Network Architecture (RINA) over packet networks, including access, metro, core and DC segments. The common umbrella of all these solutions is the Knowledge-Defined Networking (KDN)-based orchestration layer which, by implementing Artificial Intelligence (AI) techniques, enables an optimal end-to-end service provisioning. Finally, the cross-layer manager of the ALLIANCE architecture includes two novel elements, namely the monitoring element providing network and user data in real time to the KDN, and the blockchain-based trust element in charge of exchanging reliable and confident information with external domains.This work has been partially funded by the Spanish Ministry of Economy and Competitiveness under contract FEDER TEC2017-90034-C2 (ALLIANCE project) and by the Generalitat de Catalunya under contract 2017SGR-1037 and 2017SGR-605.Peer ReviewedPostprint (published version

Enabling interoperable distributed ledger technology with legacy platforms for enterprise digitalization

Presently to achieve enterprise digitalization technologies such as Distributed Ledger Technologies (DLT) has now been deployed to support digital services provided by enterprises. But several challenges in DLTs remain to be addressed, including the interoperability, standardization, and integration. Therefore, this study provides theoretical and practical understanding of DLT interoperability and identified the factors that influence the interoperability of DLTs. Also, an architecture is designed to shows how interoperability can be achieved in DLTs and legacy systems supported by Application Programming Interface (API). A case study is presented to illustrate the applicability of the architecture to support a digital energy marketplace.acceptedVersio

Post-quantum blockchain for internet of things domain

This thesis was submitted for the award of Doctor of Philosophy and was awarded by Brunel University LondonIn the evolving realm of quantum computing, emerging advancements reveal substantial challenges and threats to existing cryptographic infrastructures, particularly impacting blockchain technologies. These are pivotal for securing the Internet of Things (IoT) ecosystems. The traditional blockchain structures, integral to myriad IoT applications, are susceptible to potential quantum computations, emphasizing an urgent need for innovations in post-quantum blockchain solutions to reinforce security in the expansive domain of IoT. This PhD thesis delves into the crucial exploration and meticulous examination of the development and implementation of post-quantum blockchain within the IoT landscape, focusing on the incorporation of advanced post-quantum cryptographic algorithms in Hyperledger Fabric, a forefront blockchain platform renowned for its versatility and robustness. The primary aim is to discern viable post-quantum cryptographic solutions capable of fortifying blockchain systems against impending quantum threats enhancing security and reliability in IoT applications. The research comprehensively evaluates various post-quantum public-key generation and digital signature algorithms, performing detailed analyses of their computational time and memory usage to identify optimal candidates. Furthermore, the thesis proposes an innovative lattice-based digital signature scheme Fast-Fourier Lattice-based Compact Signature over NTRU (Falcon), which leverages the Monte Carlo Markov Chain (MCMC) algorithm as a trapdoor sampler to augment its security attributes. The research introduces a post-quantum version of the Hyperledger Fabric blockchain that integrates post-quantum signatures. The system utilizes the Open Quantum Safe (OQS) library, rigorously tested against NIST round 3 candidates for optimal performance. The study highlights the capability to manage IoT data securely on the post-quantum Hyperledger Fabric blockchain through the Message Queue Telemetry Transport (MQTT) protocol. Such a configuration ensures safe data transfer from IoT sensors directly to the blockchain nodes, securing the processing and recording of sensor data within the node ledger. The research addresses the multifaceted challenges of quantum computing advancements and significantly contributes to establishing secure, efficient, and resilient post-quantum blockchain infrastructures tailored explicitly for the IoT domain. These findings are instrumental in elevating the security paradigms of IoT systems against quantum vulnerabilities and catalysing innovations in post-quantum cryptography and blockchain technologies. Furthermore, this thesis introduces strategies for the optimization of performance and scalability of post-quantum blockchain solutions and explores alternative, energy-efficient consensus mechanisms such as the Raft and Stellar Consensus Protocol (SCP), providing sustainable alternatives to the conventional Proof-of-Work (PoW) approach. A critical insight emphasized throughout this thesis is the imperative of synergistic collaboration among academia, industry, and regulatory bodies. This collaboration is pivotal to expedite the adoption and standardization of post-quantum blockchain solutions, fostering the development of interoperable and standardized technologies enriched with robust security and privacy frameworks for end users. In conclusion, this thesis furnishes profound insights and substantial contributions to implementing post-quantum blockchain in the IoT domain. It delineates original contributions to the knowledge and practices in the field, offering practical solutions and advancing the state-of-the-art in post-quantum cryptography and blockchain research, thereby paving the way for a secure and resilient future for interconnected IoT systems

Certitex: a Textile Certified Supply Chain

The appearance of blockchain technologies and their growth and development have led to the exploration of applications of the technology in new areas, in addition to the original, cryptocurrencies, areas such as product management and traceability in supply chains are being explored. Initially, this technology was explored with the aim of providing food supply chains with traceability and transparency for the consumer. Currently, solutions for a larger variety of supply chains are being studied and developed. Current studies have proven that the technology has powerful properties to promote traceability and nonrepudiation of information related to products in a supply chain, as well as providing liability of entities for damages caused to products, which in the past has been notoriously difficult. The current structure of these supply chains, several different entities located in different physical spaces, is prone to the application of blockchain solutions as it also fits the architecture of the technology itself. All of this leads to a strong interest in applying blockchain technology to supply chains. Unfortunately, all the blockchain based solutions found to solve similar problems in the research phase of this project were developed by private entities, with little to no divulgation about their development and many times not even about how they function. This led to this project being mainly about researching the base technology and developing a solution from scratch. The problems of currently used traditional solutions are related to the use of non-standardized information registration strategies and ease of repudiation of information, but current consumer demands for knowledge of the origin of products has led to the exploration of new solutions to overcome this. Additionally, it is common for products, at the end of their production cycle, to be damaged and it is practically impossible to locate where the damage occurred in the chain. The idea of adapting blockchain technology as a solution for product traceability in the supply chain presents some points of concern, as blockchains are generally associated with distributed and public systems to maintain a given cryptocurrency, thus making information public. Although this is the initial purpose of its creation, other blockchain technologies oriented to data storage in a business to business model have emerged. These blockchains have access control measures, and are therefore called private. Only allowing access by a select group of entities. Additionally, information stored on a blockchain is also often associated with high costs, and when we refer to public blockchains like Ethereum this is a reality, but by using private solutions we can mitigate this cost. It is also often a concern the computational costs associated with cryptocurrency blockchains like Bitcoin and Etherum. Again, it is possible to get around this limitation by using private solutions where we can use more light weight algorithms, because the environment in which the system will be inserted, does not benefit from the properties of such algorithms. With the usage of blockchain to certify and record the progress of products as they travel through the supply chain, it is also interesting to explore the collected data, and how it could be used to make the supply chain itself more efficient. The purpose of this dissertation is to study how blockchain technology can be combined with a supply chain to offer product traceability and information collection. To achieve this goal, a prototype of a blockchain-based application was developed to collect data in a supply chain, as well as a prototype of an application for remote viewing of the data entered and a prototype of a Machine Learning module able to make use of the information collected by the blockchain.O aparecimento das tecnologias blockchain e o seu crescimento e desenvolvimento, têm levado à exploração de aplicações da tecnologia em novas áreas. Inicialmente, e relativamente ao tema desta tese, esta tecnologia foi explorada com o objetivo de prover cadeias de fornecimento alimentícias de rastreabilidade e transparência para o consumidor. Estudos atuais têm provado que a tecnologia apresenta propriedades poderosas para promover a rastreabilidade e não repúdio de informação. Infelizmente todas as soluções baseadas em blockchain encontradas na fase de pesquisa são soluções desenvolvidas por entidades privadas não havendo qualquer divulgação de informação relativa ao seu desenvolvimento, e também na maioria esmagadora dos casos sobre o seu funcionamento. Isto levou a que esta dissertação fosse maioritariamente um trabalho de investigação da tecnologia base, e desenvolvimento de raiz de uma solução funcional. Os problemas das soluções tradicionais, prendem-se com o uso de estratégias de registo de informação não estandardizadas e facilidade de repúdio de informação isto porque cada entidade por norma age independentemente das outras e apenas comunica com aquelas que lhe estão diretamente ligadas. Adicionalmente, é comum verificar que produtos no final da sua cadeia de produção estão danificados e de ser praticamente impossível localizar onde na cadeia os danos ocorreram. A ideia de adaptar a tecnologia blockchain como uma solução para a rastreabilidade de produtos na cadeia de fornecimento apresenta alguns pontos preocupantes, pois as blockchains são geralmente associadas a sistemas distribuídos e públicos para manter uma dada criptomoeda. Apesar de este ser o propósito inicial para a sua criação têm vindo a surgir outras tecnologias blockchain orientadas para o armazenamento e processamento de dados num modelo business to business. Estas blockchains possuem medidas de controlo de acesso, e são, portanto chamadas de privadas permitindo apenas acesso por parte de um grupo seleto de entidades. Adicionalmente, o armazenamento de informação numa blockchain é também muitas vezes associado a custos elevados, e quando nos referimos a blockchains públicas como a Ethereum isto é uma realidade, mas pelo uso de soluções privadas podemos colmatar este custo. É também uma preocupação os custos computacionais associados a blockchains de criptomoeadas como a Bitcoin e Etherum. Novamente é possível contornar esta limitação pelo uso de soluções privativas onde podemos usar algoritmos mais leves, pois o ambiente em que o sistema se vai inserir, não carece de tantos cuidados. Através do uso de blockchain para certificar a origem e percurso de produtos numa cadeia de fornecimento é também interessante explorar os dados recolhidos no processo e como estes podem ser utilizados para tornar a própria cadeia de fornecimentos mais eficiente. O objetivo desta dissertação é estudar como a tecnologia blockchain pode ser conjugada com uma cadeia de fornecimento para oferecer rastreabilidade de produtos e recolha de informação. Para alcançar este objetivo foi desenvolvido um protótipo de uma aplicação baseada em blockchain para recolha de dados numa cadeia de fornecimento, bem como um protótipo de uma aplicação para a visualização e interação remota com os dados e também um protótipo de um módulo de Machine Learning capaz de fazer uso da informação recolhida pela blockchain

Collaborative autonomy in heterogeneous multi-robot systems

As autonomous mobile robots become increasingly connected and widely deployed in different domains, managing multiple robots and their interaction is key to the future of ubiquitous autonomous systems. Indeed, robots are not individual entities anymore. Instead, many robots today are deployed as part of larger fleets or in teams. The benefits of multirobot collaboration, specially in heterogeneous groups, are multiple. Significantly higher degrees of situational awareness and understanding of their environment can be achieved when robots with different operational capabilities are deployed together. Examples of this include the Perseverance rover and the Ingenuity helicopter that NASA has deployed in Mars, or the highly heterogeneous robot teams that explored caves and other complex environments during the last DARPA Sub-T competition. This thesis delves into the wide topic of collaborative autonomy in multi-robot systems, encompassing some of the key elements required for achieving robust collaboration: solving collaborative decision-making problems; securing their operation, management and interaction; providing means for autonomous coordination in space and accurate global or relative state estimation; and achieving collaborative situational awareness through distributed perception and cooperative planning. The thesis covers novel formation control algorithms, and new ways to achieve accurate absolute or relative localization within multi-robot systems. It also explores the potential of distributed ledger technologies as an underlying framework to achieve collaborative decision-making in distributed robotic systems. Throughout the thesis, I introduce novel approaches to utilizing cryptographic elements and blockchain technology for securing the operation of autonomous robots, showing that sensor data and mission instructions can be validated in an end-to-end manner. I then shift the focus to localization and coordination, studying ultra-wideband (UWB) radios and their potential. I show how UWB-based ranging and localization can enable aerial robots to operate in GNSS-denied environments, with a study of the constraints and limitations. I also study the potential of UWB-based relative localization between aerial and ground robots for more accurate positioning in areas where GNSS signals degrade. In terms of coordination, I introduce two new algorithms for formation control that require zero to minimal communication, if enough degree of awareness of neighbor robots is available. These algorithms are validated in simulation and real-world experiments. The thesis concludes with the integration of a new approach to cooperative path planning algorithms and UWB-based relative localization for dense scene reconstruction using lidar and vision sensors in ground and aerial robots