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ICT for Health: Networks, standards and innovation

blockchain applications such as those identified by [3], in against dimensions of time to achieve consistency, system
this paper the focus is on application areas that are uniquely availability, failure tolerance, scalability, latency,
related to healthcare, rather than application areas like auditability, liveliness, denial of service resistance and
payments for services by bitcoin that may be broadly system complexity. Standardized benchmarks and targets for
applicable across a number of industries. [25] identified the healthcare blockchain performance have not yet been
major stakeholders in digital health systems as patients, the identified.
public, healthcare professionals and health administrators;
however, regulatory agencies and legal systems may also Software engineering has developed tools and methods to
need to be able to operate on or interact with the healthcare support the development and operation of software systems,
blockchains. Provisions would also be needed for minors, but to date these are not optimized for blockchain systems.
access under a healthcare power of attorney, and in some [32] identifies the features and implementation challenges of
cases access after death by heirs. interoperability for healthcare blockchain applications and
proposes foundational software patterns to help address them.
3. TECHNOLOGY ISSUES [33] identifies blockchain oriented software engineering
challenges as new professional roles, security and reliability,
Technology issues can be seen as risks impeding design and software architecture, modeling languages and metrics, and
deployment of healthcare blockchains. Ethereum and proposes new directions for blockchain oriented software
Hyperledger were the most frequently mentioned blockchain engineering related to enhancement of testing and debugging
implementation technologies, found by [17] but only 2% of for specific programming languages and the creation of
the papers surveyed were reporting on implementations, so software tools for smart contract languages. [34] echoes the
healthcare blockchains are still at the early stages of adoption. call for further development of blockchain oriented software
There is not one blockchain but a variety of implementations engineering best practices and design patterns.
with different characteristics [26],[27] (even bitcoin has
forked). Identified technology challenges to the development 3.2 Identity and trust issues in healthcare
of healthcare blockchains include interoperability, security blockchains
and privacy, scalability, speed and patient engagement [14].
Interoperability, scalability and speed are characteristics of Many of the benefits (e.g. improved data security and
the software implementation of healthcare applications on privacy, health data ownership, transparency and trust, data
the blockchain. The degree of patient engagement can be verifiability, non-repudiation, data provenance) sought from
significantly impacted by not just the implementation and healthcare blockchains rely on some form of trust. To
trust issues, but also the usability of the system and the achieve their healthcare objectives, patients need to trust
overall user experience with the healthcare blockchain. healthcare providers. Patients and healthcare professionals
Security, privacy and trust issues reflect concerns about not need to trust the validity of data used for diagnosis and
just the implementation, but the processes for assuring the treatment. Trust has been defined in many different ways by
users can trust the blockchain and its associated software, as different researchers. [35] proposed an interdisciplinary
well as the organizational and legal context. [28] points out model of trust involving components for disposition to trust,
that health information technology in general needs to institution-based trust, trusting beliefs and trusting intentions.
consider not just clinical information, but also socio- Since literally everyone is potentially a patient, and patients
technical concepts of value and trust concepts to be are actors in most healthcare blockchains, addressing all of
successful. those trust components may be necessary for the broad
adoption of healthcare blockchains; not all of them, however,
3.1 Implementation issues in healthcare blockchains are directly solved by blockchains. Disposition to trust and
institution-based trust lie more in the realm of psychological,
Healthcare blockchain applications, whether directly on the sociological and economic concepts. Trusting beliefs and
blockchain, or smart contracts or DAOs, are all software; and intentions may be more manageable for healthcare
software bugs impact the functionality and quality of blockchains that are explicit about what actors can rely on
blockchain systems. [29] performed an empirical study of and for what purposes in the healthcare blockchain use cases.
over one thousand bugs identified from 19 open source
blockchain systems categorizing them and studying their Because of the use of blockchain technology in the financial
resolution to determine that the frequency distributions of industry, and the associated loss risks, the security of
bug types share similar trends across the studied projects, blockchains and related smart contracts have received
implying that these would apply to healthcare blockchain significant attention. In a survey on the security of
applications also. They noted that security bugs took the blockchain systems [36] proposed a taxonomy of the targets
longest median time to fix and that more than 35% of of security attacks. For Blockchain 1.0 (cryptocurrency)
performance bugs took more than a year to fix. While not blockchains the targets were the blockchain consensus
providing specific metrics, [30] identified dimensions for the mechanism, the public key encryption scheme, the
quality of blockchain implementations as including security, cryptocurrency application criminal activity (e.g. money
privacy, throughput, size and bandwidth, performance, laundering ransomware), the transaction verification
usability, data integrity and scalability. [31] surveyed the mechanism, and transaction design flaws that could lead to
performance characteristics of six different blockchains privacy leakage. For Blockchain 2.0 (smart contract)

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