Towards the Uses of Blockchain in Mobile Health Services and Applications: A Survey <s> Blockchain Technology: The Road So Far <s> Recent developments in "cryptocurrencies" and "smart contracts" are creating new opportunities for applying AI techniques. These economic technologies would benefit from greater real world knowledge and reasoning as they become integrated with everyday commerce. Cryptocurrencies and smart contracts may also provide an infrastructure for ensuring that AI systems follow specified legal and safety regulations as they become more integrated into human society. <s> BIB001 </s> Towards the Uses of Blockchain in Mobile Health Services and Applications: A Survey <s> Blockchain Technology: The Road So Far <s> A smart city uses information technology to integrate and manage physical, social, and business infrastructures in order to provide better services to its dwellers while ensuring efficient and optimal utilization of available resources. With the proliferation of technologies such as Internet of Things (IoT), cloud computing, and interconnected networks, smart cities can deliver innovative solutions and more direct interaction and collaboration between citizens and the local government. Despite a number of potential benefits, digital disruption poses many challenges related to information security and privacy. This paper proposes a security framework that integrates the blockchain technology with smart devices to provide a secure communication platform in a smart city. <s> BIB002 </s> Towards the Uses of Blockchain in Mobile Health Services and Applications: A Survey <s> Blockchain Technology: The Road So Far <s> Swarms of robots will revolutionize many industrial applications, from targeted material delivery to precision farming. However, several of the heterogeneous characteristics that make them ideal for certain future applications --- robot autonomy, decentralized control, collective emergent behavior, etc. --- hinder the evolution of the technology from academic institutions to real-world problems. Blockchain, an emerging technology originated in the Bitcoin field, demonstrates that by combining peer-to-peer networks with cryptographic algorithms a group of agents can reach an agreement on a particular state of affairs and record that agreement without the need for a controlling authority. The combination of blockchain with other distributed systems, such as robotic swarm systems, can provide the necessary capabilities to make robotic swarm operations more secure, autonomous, flexible and even profitable. This work explains how blockchain technology can provide innovative solutions to four emergent issues in the swarm robotics research field. New security, decision making, behavior differentiation and business models for swarm robotic systems are described by providing case scenarios and examples. Finally, limitations and possible future problems that arise from the combination of these two technologies are described. <s> BIB003 </s> Towards the Uses of Blockchain in Mobile Health Services and Applications: A Survey <s> Blockchain Technology: The Road So Far <s> In the Internet of Things (IoT) scenario, the block-chain and, in general, Peer-to-Peer approaches could play an important role in the development of decentralized and dataintensive applications running on billion of devices, preserving the privacy of the users. Our research goal is to understand whether the blockchain and Peer-to-Peer approaches can be employed to foster a decentralized and private-by-design IoT. As a first step in our research process, we conducted a Systematic Literature Review on the blockchain to gather knowledge on the current uses of this technology and to document its current degree of integrity, anonymity and adaptability. We found 18 use cases of blockchain in the literature. Four of these use cases are explicitly designed for IoT. We also found some use cases that are designed for a private-by-design data management. We also found several issues in the integrity, anonymity and adaptability. Regarding anonymity, we found that in the blockchain only pseudonymity is guaranteed. Regarding adaptability and integrity, we discovered that the integrity of the blockchain largely depends on the high difficulty of the Proof-of-Work and on the large number of honest miners, but at the same time a difficult Proof-of-Work limits the adaptability. We documented and categorized the current uses of the blockchain, and provided a few recommendations for future work to address the above-mentioned issues. <s> BIB004 </s> Towards the Uses of Blockchain in Mobile Health Services and Applications: A Survey <s> Blockchain Technology: The Road So Far <s> Motivated by the recent explosion of interest around blockchains, we examine whether they make a good fit for the Internet of Things (IoT) sector. Blockchains allow us to have a distributed peer-to-peer network where non-trusting members can interact with each other without a trusted intermediary, in a verifiable manner. We review how this mechanism works and also look into smart contracts—scripts that reside on the blockchain that allow for the automation of multi-step processes. We then move into the IoT domain, and describe how a blockchain-IoT combination: 1) facilitates the sharing of services and resources leading to the creation of a marketplace of services between devices and 2) allows us to automate in a cryptographically verifiable manner several existing, time-consuming workflows. We also point out certain issues that should be considered before the deployment of a blockchain network in an IoT setting: from transactional privacy to the expected value of the digitized assets traded on the network. Wherever applicable, we identify solutions and workarounds. Our conclusion is that the blockchain-IoT combination is powerful and can cause significant transformations across several industries, paving the way for new business models and novel, distributed applications. <s> BIB005 </s> Towards the Uses of Blockchain in Mobile Health Services and Applications: A Survey <s> Blockchain Technology: The Road So Far <s> Blockchain technology has attracted tremendous attention in both academia and capital market. However, overwhelming speculations on thousands of available cryptocurrencies and numerous initial coin offering (ICO) scams have also brought notorious debates on this emerging technology. This paper traces the development of blockchain systems to reveal the importance of decentralized applications (dApps) and the future value of blockchain. We survey the state-of-the-art dApps and discuss the direction of blockchain development to fulfill the desirable characteristics of dApps. The readers will gain an overview of dApp research and get familiar with recent developments in the blockchain. <s> BIB006 </s> Towards the Uses of Blockchain in Mobile Health Services and Applications: A Survey <s> Blockchain Technology: The Road So Far <s> Blockchain is considered one of the most disruptive technologies of our time. Numerous cities around the world are launching blockchain initiatives as part of the overall efforts toward shaping the urban future. However, the infancy stage of the blockchain industry leads to a severe gap between the knowledge we have and the actions urban policy makers are taking. This paper is an effort to narrow this rift. We provide a systematic literature review on concrete blockchain use cases proposed by the research community. At the macro-level, we discuss and organize use cases from 159 selected papers into nine sectors recognized as crucial for sustainable and smart urban future. At the micro-level, we identify a component-based framework and analyze the design and prototypes of blockchain systems studied in a subset of 71 papers. The high-level use case review allows us to illustrate the relationship between them and the four pillars of urban sustainability: social, economic, environmental, and governmental. The system level analysis helps us highlight interesting inconsistencies between well-known blockchain applicability decision rules and the approaches taken by the literature. We also offer two classification methodologies for blockchain use cases and elaborate on how they can be applied to stimulate cross-sector insights in the blockchain knowledge domain. <s> BIB007 </s> Towards the Uses of Blockchain in Mobile Health Services and Applications: A Survey <s> Blockchain Technology: The Road So Far <s> With the rapid growth of urbanization, smart city needs efficient and sustainable intelligent solutions in the transportation, environment, energy, government affairs. The smart city infrastructure, which combines the IoT, Big Data and Energy Internet, is one of the most effective solutions. It’s facing many problems such as poor security of IoT, equipment maintenance and upgrade difficulty, high operating costs of large data center construction, poor resistance to damage, the difficulty of establishing the energy Internet users trust , user privacy is easy to leak, market model is not applicable and so on. The Blockchain is a kind of distributed P2P network common intelligence accounting technology based on cryptography. The features of open, transparent, interconnection and peer-to-peer, storage and sharing in the Blockchain are relevant to the openness, interconnection, peer-to-peer and Shared characteristics of the energy Internet. Its features of redundant storage and distribution also make up for the disadvantages of large data center’s high operation cost, poor recovery ability and the difficulties for the maintenance of IoT equipment. This paper, first introduces the role of the big data, IoT, and the energy Internet in the construction of smart city and Blockchain technology. By analyzing their respective characteristics and comparing their similarities, corresponding solutions are put forward to aim at the problems such as poor security of IoT, upgrading of equipment maintenance and upgrading, construction and operation cost of large data center, poor flexibility in anti-attack, difficulty in establishing trust in energy Internet users, user privacy leakage and inapplicability of trading market mode. A kind of architecture of P2P light-heavy backup is put forward to overcome the high cost of Blockchain data storage. <s> BIB008 </s> Towards the Uses of Blockchain in Mobile Health Services and Applications: A Survey <s> Blockchain Technology: The Road So Far <s> While the smart surveillance system enhanced by the Internet of Things (IoT) technology becomes an essential part of Smart Cities, it also brings new concerns in security of the data. Compared to the traditional surveillance systems that is built following a monolithic architecture to carry out lower level operations, such as monitoring and recording, the modern surveillance systems are expected to support more scalable and decentralized solutions for advanced video stream analysis at the large volumes of distributed edge devices. In addition, the centralized architecture of the conventional surveillance systems is vulnerable to single point of failure and privacy breach owning to the lack of protection to the surveillance feed. This position paper introduces a novel secure smart surveillance system based on microservices architecture and blockchain technology. Encapsulating the video analysis algorithms as various independent microservices not only isolates the video feed from different sectors, but also improve the system availability and robustness by decentralizing the operations. The blockchain technology securely synchronizes the video analysis databases among microservices across surveillance domains, and provides tamper proof of data in the trustless network environment. Smart contract enabled access authorization strategy prevents any unauthorized user from accessing the microservices and offers a scalable, decentralized and fine-grained access control solution for smart surveillance systems. <s> BIB009 </s> Towards the Uses of Blockchain in Mobile Health Services and Applications: A Survey <s> Blockchain Technology: The Road So Far <s> It is undeniable that artificial intelligence (AI) and blockchain concepts are spreading at a phenomenal rate. Both technologies have distinct degree of technological complexity and multi-dimensional business implications. However, a common misunderstanding about blockchain concept, in particular, is that blockchain is decentralized and is not controlled by anyone. But the underlying development of a blockchain system is still attributed to a cluster of core developers. Take smart contract as an example, it is essentially a collection of codes (or functions) and data (or states) that are programmed and deployed on a blockchain (say, Ethereum) by different human programmers. It is thus, unfortunately, less likely to be free of loopholes and flaws. In this article, through a brief overview about how artificial intelligence could be used to deliver bug-free smart contract so as to achieve the goal of blockchain 2.0, we to emphasize that the blockchain implementation can be assisted or enhanced via various AI techniques. The alliance of AI and blockchain is expected to create numerous possibilities. <s> BIB010 </s> Towards the Uses of Blockchain in Mobile Health Services and Applications: A Survey <s> Blockchain Technology: The Road So Far <s> The paradigm of Internet of Things (IoT) is paving the way for a world, where many of our daily objects will be interconnected and will interact with their environment in order to collect information and automate certain tasks. Such a vision requires, among other things, seamless authentication, data privacy, security, robustness against attacks, easy deployment, and self-maintenance. Such features can be brought by blockchain, a technology born with a cryptocurrency called Bitcoin. In this paper, a thorough review on how to adapt blockchain to the specific needs of IoT in order to develop Blockchain-based IoT (BIoT) applications is presented. After describing the basics of blockchain, the most relevant BIoT applications are described with the objective of emphasizing how blockchain can impact traditional cloud-centered IoT applications. Then, the current challenges and possible optimizations are detailed regarding many aspects that affect the design, development, and deployment of a BIoT application. Finally, some recommendations are enumerated with the aim of guiding future BIoT researchers and developers on some of the issues that will have to be tackled before deploying the next generation of BIoT applications. <s> BIB011 </s> Towards the Uses of Blockchain in Mobile Health Services and Applications: A Survey <s> Blockchain Technology: The Road So Far <s> The recent expansion of the Internet of Things (IoT) and the consequent explosion in the volume of data produced by smart devices have led to the outsourcing of data to designated data centers. However, to manage these huge data stores, centralized data centers, such as cloud storage cannot afford auspicious way. There are many challenges that must be addressed in the traditional network architecture due to the rapid growth in the diversity and number of devices connected to the internet, which is not designed to provide high availability, real-time data delivery, scalability, security, resilience, and low latency. To address these issues, this paper proposes a novel blockchain-based distributed cloud architecture with a software defined networking (SDN) enable controller fog nodes at the edge of the network to meet the required design principles. The proposed model is a distributed cloud architecture based on blockchain technology, which provides low-cost, secure, and on-demand access to the most competitive computing infrastructures in an IoT network. By creating a distributed cloud infrastructure, the proposed model enables cost-effective high-performance computing. Furthermore, to bring computing resources to the edge of the IoT network and allow low latency access to large amounts of data in a secure manner, we provide a secure distributed fog node architecture that uses SDN and blockchain techniques. Fog nodes are distributed fog computing entities that allow the deployment of fog services, and are formed by multiple computing resources at the edge of the IoT network. We evaluated the performance of our proposed architecture and compared it with the existing models using various performance measures. The results of our evaluation show that performance is improved by reducing the induced delay, reducing the response time, increasing throughput, and the ability to detect real-time attacks in the IoT network with low performance overheads. <s> BIB012 </s> Towards the Uses of Blockchain in Mobile Health Services and Applications: A Survey <s> Blockchain Technology: The Road So Far <s> Robotic events can provide notable amounts of information regarding a robot's status, which can be extrapolated to detect productivity, anomalies, malfunctions and used for monitorization. However, when problems occur in sensitive environments like a factory, the logs of a machine may be discarded because they are susceptible to chances and malicious intents. In this paper we propose to use RobotChain for anomaly detection. RobotChain is a method to securely register robotic events, using a blockchain, which ensures that once an event gets registered on it, it's secured and cannot be tampered with. We show how this system can be leveraged with the module for anomaly detection, that uses the information contained on the blockchain to detect anomalies on a UR3 robot. <s> BIB013 </s> Towards the Uses of Blockchain in Mobile Health Services and Applications: A Survey <s> Blockchain Technology: The Road So Far <s> Blockchain is a disruptive technology that is normally used within financial applications, however it can be very beneficial also in certain robotic contexts, such as when an immutable register of events is required. Among the several properties of Blockchain that can be useful within robotic environments, we find not just immutability but also decentralization of the data, irreversibility, accessibility and non-repudiation. In this paper, we propose an architecture that uses blockchain as a ledger and smart-contract technology for robotic control by using external parties, Oracles, to process data. We show how to register events in a secure way, how it is possible to use smart-contracts to control robots and how to interface with external Artificial Intelligence algorithms for image analysis. The proposed architecture is modular and can be used in multiple contexts such as in manufacturing, network control, robot control, and others, since it is easy to integrate, adapt, maintain and extend to new domains. <s> BIB014
The state of the art in blockchain is mainly defined by relevant research work and implementations of either the classic blockchain protocol or some new modification of it, not exactly new constructions of the protocol itself. In fact, slight modifications of the protocol started being incorporated into various fields of digital activity. This first started as blockchain 1.0, a term describing a distributed ledger used in the control of cryptocurrencies such as Bitcoin. The process of generalizing what the blockchain protocol could be used for peaked when the concept of a program that can be triggered to execute automatically was added to a block. This originated the concept of a smart contract, creating what is now known as blockchain 2.0 and its prime example being Ethereum  . Further innovation on the possible uses of smart contracts and the decentralized nature of blockchain led to the research into decentralized applications. These, so called DApps applications, make use of both decentralized storage and communication for their operation  , BIB006 . Currently, cutting-edge research is underway in order to harness the capabilities explored in previous modifications on the usage of blockchain technology in an industry or standard infrastructural development context. This research focuses on aspects such as resource planning, automation and interoperability BIB007 , BIB008 , BIB002 , BIB009 . Unibright, a platform designed in early 2018, aims to integrate the advantages of blockchain without the sharp rise in complexity for business, handling the creation of workflows and smartcontracts automatically  , already managing to advance in integrating SAP  into its platform  . Implementations following the blockchain 1.0 are already commonly understood and studied, and therefore, they are commonly mixed with other implementations that adapt characteristics more aligned with blockchain 2.0 or even 3.0. The most widely known example of this, presents itself in the form of Bitcoin and Ethereum. Although they function based on the same underlying protocol, they have glar-ing differences in their structure, capabilities and purpose. Ether  ,  is the name of the token used by the Ethereum platform  ,  to reward participants who successfully solve a challenge linked to the verification or validation of a transaction. Ether is different from Bitcoin in the way that it is not supposed to represent a currency in and of itself, but an incentive aimed at participants that contribute with computational resources to the network. The main appeal of Ethereum comes in the form of smartcontracts, software written using the programming language Solidity, that are to be executed on the Ethereum network. These smart-contracts are, in essence, a way to force different parties to exchange something of value to one another in an autonomous way when the contract is executed in the network, regardless of how long ago it was made. What makes this technology so powerful is that these contracts are immune to third-party or middleman interference and are immutable once added to the blockchain, providing auditability and an immutable history of contractual transactions  . The blockchain protocol has been extensively modified and several new interesting features have been discovered and adapted into existing or entirely new systems. As an example, Tezos  , a crypto-ledger implemented in OCaml [114] , aims to emulate the working of other blockchains but with mutable and evolving protocols that can adjust themselves to changes that are proposed and voted by the participants of the network  . Therefore, it aims to be able to change its format and meta according to evolving situations and necessities, without the need to fork the blockchain. Another field where blockchain seems to be having fair growth is in artificial intelligence. Cutting-edge research work  ,  , BIB010 , BIB001 aims to adapt the information recording capabilities of blockchain into the data collection processes of artificial systems. Currently, a fair number of proposals indicate that from the integration of blockchain into robotic systems backed by artificial intelligence, several improvements in the productivity of these systems in production environments can be achieved  , BIB013 , BIB003 , BIB014 ,  . By using smart-contracts to store information, triggers can be made so that certain tasks are automated when a certain contract is executed. Proposals for the use of these characteristics in conjunction with artificial intelligence systems range from integrating blockchain into cognitive commerce platforms  to the health field  , [125] . In addition, research regarding the integration of blockchain technology into the internet of things shows promise. It aims to allow automatic contracts to be carried out when receiving a network command and then recording event data into the blockchain BIB004 , BIB011 , BIB005 . Research into the security aspects of blockchain implementations aims to simplify future implementations by adapting existing security solutions to work with blockchain-backed systems  , BIB012 .