Towards the Uses of Blockchain in Mobile Health Services and Applications: A Survey <s> Blockchain in Healthcare <s> The technology likely to have the greatest impact on the future of the world economy has arrived, and its not self-driving cars, solar energy, or artificial intelligence. Its called the blockchain. The first generation of the digital revolution brought us the Internet of information. The second generationpowered by blockchain technologyis bringing us the Internet of value: a new, distributed platform that can help us reshape the world of business and transform the old order of human affairs for the better. Blockchain is the ingeniously simple, revolutionary protocol that allows transactions to be simultaneously anonymous and secure by maintaining a tamperproof public ledger of value. Though its the technology that drives bitcoin and other digital currencies, the underlying framework has the potential to go far beyond these and record virtually everything of value to humankind, from birth and death certificates to insurance claims and even votes. Why should you care? Maybe youre a music lover who wants artists to make a living off their art. Or a consumer who wants to know where that hamburger meat really came from. Perhaps youre an immigrant whos sick of paying big fees to send money home to loved ones. Or an entrepreneur looking for a new platform to build a business. And those examples are barely the tip of the iceberg. This technology is public, encrypted, and readily available for anyone to use. Its already seeing widespread adoption in a number of areas. For example, forty-two (and counting) of the worlds biggest financial institutions, including Goldman Sachs, JPMorgan Chase, and Credit Suisse, have formed a consortium to investigate the blockchain for speedier and more secure transactions. As with major paradigm shifts that preceded it, the blockchain will create winners and losers. And while opportunities abound, the risks of disruption and dislocation must not be ignored. Don Tapscott, the bestselling author of Wikinomics, and his son, blockchain expert Alex Tapscott, bring us a brilliantly researched, highly readable, and utterly foundational book about the future of the modern economy. Blockchain Revolution is the business leaders playbook for the next decade and beyond. <s> BIB001 </s> Towards the Uses of Blockchain in Mobile Health Services and Applications: A Survey <s> Blockchain in Healthcare <s> Enabled by mobile and wearable technology, personal health data delivers immense and increasing value for healthcare, benefiting both care providers and medical research. The secure and convenient sharing of personal health data is crucial to the improvement of the interaction and collaboration of the healthcare industry. Faced with the potential privacy issues and vulnerabilities existing in current personal health data storage and sharing systems, as well as the concept of self-sovereign data ownership, we propose an innovative user-centric health data sharing solution by utilizing a decentralized and permissioned blockchain to protect privacy using channel formation scheme and enhance the identity management using the membership service supported by the blockchain. A mobile application is deployed to collect health data from personal wearable devices, manual input, and medical devices, and synchronize data to the cloud for data sharing with healthcare providers and health insurance companies. To preserve the integrity of health data, within each record, a proof of integrity and validation is permanently retrievable from cloud database and is anchored to the blockchain network. Moreover, for scalable and performance considerations, we adopt a tree-based data processing and batching method to handle large data sets of personal health data collected and uploaded by the mobile platform. <s> BIB002 </s> Towards the Uses of Blockchain in Mobile Health Services and Applications: A Survey <s> Blockchain in Healthcare <s> Since its inception, the blockchain technology has shown promising application prospects. From the initial cryptocurrency to the current smart contract, blockchain has been applied to many fields. Although there are some studies on the security and privacy issues of blockchain, there lacks a systematic examination on the security of blockchain systems. In this paper, we conduct a systematic study on the security threats to blockchain and survey the corresponding real attacks by examining popular blockchain systems. We also review the security enhancement solutions for blockchain, which could be used in the development of various blockchain systems, and suggest some future directions to stir research efforts into this area. <s> BIB003 </s> Towards the Uses of Blockchain in Mobile Health Services and Applications: A Survey <s> Blockchain in Healthcare <s> Blockchain technologies are gaining massive momentum in the last few years. Blockchains are distributed ledgers that enable parties who do not fully trust each other to maintain a set of global states. The parties agree on the existence, values and histories of the states. As the technology landscape is expanding rapidly, it is both important and challenging to have a firm grasp of what the core technologies have to offer, especially with respect to their data processing capabilities. In this paper, we first survey the state of the art, focusing on private blockchains (in which parties are authenticated). We analyze both in-production and research systems in four dimensions: distributed ledger, cryptography, consensus protocol and smart contract. We then present BLOCKBENCH, a benchmarking framework for understanding performance of private blockchains against data processing workloads. We conduct a comprehensive evaluation of three major blockchain systems based on BLOCKBENCH, namely Ethereum, Parity and Hyperledger Fabric. The results demonstrate several trade-offs in the design space, as well as big performance gaps between blockchain and database systems. Drawing from design principles of database systems, we discuss several research directions for bringing blockchain performance closer to the realm of databases. <s> BIB004 </s> Towards the Uses of Blockchain in Mobile Health Services and Applications: A Survey <s> Blockchain in Healthcare <s> One particular trend observed in healthcare is the progressive shift of data and services to the cloud, partly due to convenience (e.g. availability of complete patient medical history in real-time) and savings (e.g. economics of healthcare data management). There are, however, limitations to using conventional cryptographic primitives and access control models to address security and privacy concerns in an increasingly cloud-based environment. In this paper, we study the potential to use the Blockchain technology to protect healthcare data hosted within the cloud. We also describe the practical challenges of such a proposition and further research that is required. <s> BIB005
With the advent of Bitcoin, the research of blockchain technologies on areas not directly linked with cryptocurrencies or data encryption has grown. This research has had far reaching influence in areas where before the inclusion of cryptographic technology in the core technologies that were already in use was not considered. It is especially noticeable with the development of smart contracts, stocks and bond trading, record keeping and even cloud storage solutions BIB001 . In fact, the biggest and most exciting thing about Bitcoin is not Bitcoin at all, it is the blockchain protocol  . The blockchain protocol is, in its essence, a digital distributed ledger that is composed of digital transactions and shared through a network. This protocol is based on a Peer-to-Peer architecture, with every participant forming a node in the network. These participants store an identical copy of the ledger and then work together in the process of validating and certifying digital transactions, adding new transactions to the ledger. The process of adding transactions is based on evaluating the proposed transaction and submitting it to a vote. If the majority of the participants find the transaction to be valid, then it is added to the ledger, linking it with the previous transaction, forming a chain that cannot be altered without breaking its integrity. Each transaction that goes through the linking process is gathered in a block, which additionally contains a cryptographic hash of the previous block, and is then linearly added in chronological order to the ledger. This process can be seen in 1. Changes to the ledger are replicated throughout the whole network and, because of this, every participant has a complete copy of the updated ledger. This also means that no single participant has the ability to easily attack the whole distributed network BIB003 .While the notion of transaction remains, the data associated with one can be of any type, as the blockchain simply links data that is stored within it. The format of the transactions is defined by the underlying network supporting the blockchain, while the data present in them is defined by the participants who create them. This data can be encrypted and digitally signed in order to add additional advantages to the system such as authenticity, integrity and non-repudiation. The transactions are added to the chain when a specific consensus mechanism is verified. Some examples of consensus mechanisms are proof-of-work, proof-of-stake or proof-of importance, with several modifications in between. Following the abovementioned comparison with Bitcoin, a proof-of-work consensus mechanism is in place where network participants try to solve challenges utilizing their computing resources. When a challenge is successfully solved, a token specific to the blockchain platform that is in use is awarded to the user that managed to solve it. When a network participant manages to validate a pending transaction so it can be added to the chain, he is then rewarded with a certain number of Bitcoin, that he can then use as a normal currency. This way, there is an incentive for participants to help in the platform performance. BIB004 , [94] Several properties of the blockchain protocol are expected to deliver improvements when applied to the health industry. These properties are fundamentally gained when the storage method of healthcare data is adapted to take advantage of the blockchain mechanisms mentioned above. The fundamental blockchain characteristics for e-health improvement are its ubiquitous and secure network infrastructure, the verifiability and authentication of the identity of its participants, as well as the security it offers in terms of data integrity, reliability, accessibility and an immutable history of all transactions BIB002 . But how do these properties compare against traditional e-health systems? First, due to its ubiquitous, anonymous but verifiable nature, the access and control of healthcare data by the patients is promoted. This is due to the chain being openly available to the public and not be bound to a remote secure database in a health care service provider own server. In addition, the methods to audit interactions are built into the blockchain itself, allowing for greater control and monitoring of access. Important information such accessed the data identification, access date, location and with what authority the data was accessed can be quickly recorded. Also, because of the cryptographic hash built into each block of the blockchain, it is possible to know if any of the previous blocks were tampered with in any way. If they were, the correct version of the chain can be easily collected from another network participant, due to its distributed nature BIB005 . In general, the healthcare industry can benefit in terms of data privacy, control, access and safety, as well as accountability and identity verification  . In terms of the IT platform that supports current health systems, several advantages arise from the integration of blockchain, mostly due to the open and distributed nature of the software. These advantages include more effective operations between different IT platforms in the health ecosystem and between these platforms and patients. This ease of use stems from using open APIs to exchange data, as well as increasing the reliability of the data storage method. In addition, as data is distributed to several different locations, it lowers the risk that a severe database malfunction would compromise data of several different patients. The advantages of the adaptation of blockchain mechanisms to the m-Health field add to the ones mentioned previously. This is due to the fact that the use of blockchain technologies in conjunction with data stored in the cloud can have a profound impact on the way that m-Health applications store and use user's data. Moreover, blockchain technology promotes the effectiveness, reliability and credibility of data access management, which helps the m-Health field to be an accepted and more mainstream complement to traditional health systems. To achieve successful uses in m-Health, key elements such as scalability and data privacy in both access to the user device and the main remote storage have to be considered. A simple scenario that shows the advantage of applying blockchain to m-Health over the more traditional systems can be seen in figure2 and 3. Can also guarantee data anonymity in the data server by encrypting the identifiable metrics from the patient health data.