Most people in tech have heard of Bitcoin, the cryptocurrency that is exciting libertarians and central bankers alike.
At its heart, Bitcoin and related technologies can be seen as ‘open ledgers’ in which transactions are recorded in a very public way, and can’t be repudiated.
The gist is that the open ledger can be trusted, even though there is no central authority vouching for it, because of the way it is implemented.
The system of maintaining the ledger is the decentralised processing of the blockchain. Could this be applied to digital health?
What is ‘Blockchain’?
As I understand it, the blockchain itself is a general formula for recording transactions in a resilient open ledger, using encryption, digital signatures, and harnessing motivation within a network of users.
Multiple participants can exchange value tokens and have that transaction recorded reliably in many places that synchronise efficiently, so that information is generally freely available. Many copies are kept of the blockchain – at least as many as the participants.
As the name suggests, the ‘database’ storing the ledger is a chain of blocks, accumulated at regular time intervals, each of which is a digitally signed document that records transactions.
By reading up and down the blockchain, you can calculate the value of any given account, including its incoming and outgoing payments. Because of the mathematical properties of how they are recorded, you can trust that the values are true.
Another important concept is that there is a sub-group within the network who make a living by renting their compute capacity.
This is to take on the cryptographical and computational burden that underpins the trust, non-repudiation and value mechanism; these people are called ‘miners’.
The use of encryption means that users are neither anonymous nor public – in something like Bitcoin, participants can choose which accounts they associate themselves with publicly and which they use to save value privately.
But in both cases the value and accounts themselves are open to scrutiny. It is their association in public that is key to understanding privacy on Bitcoin and similar platforms.
What is ‘Ehereum’?
Blockchain is not just about Bitcoin. Many related efforts use economic modelling, game theory and the techniques of digital signature to implement interesting frameworks for distributed organisations or communities over the internet.
Blockchain may be relevant to your business or community, but where do you start, and should you buy or build the technology? (Free hint – don’t build it).
Ethereum is a platform for using blockchain technology in creative ways in different markets. In some sense, it allows you to create a market.
It allows developers to use a virtual currency (‘ether’) to form the basis for smart contracts that make sense within their specific domain. In the same way was we talk about ‘monetising’ business models, to apply blockchain to your domain you need to map an aspect of the domain to the token value.
For example, we might link tokens to the generation of electricity in a decentralised power grid, and users could buy and sell power based on those units. Or we could implement a distributed voting system. Defining the contract is the specialisation step to apply the technology to your particular domain.
Ethereum itself is a not-for profit organization, based out of Zug in Switzerland, that is managing the crowdfunded development of the platform. There’s a software development organisation, ETHDEV, delivering the implementation.
That is interesting from a number of perspectives – in health in the UK, there are emerging models of community interest companies fostering the development and adoption of software platforms.
The NHS England Open Source Programme recognises that this kind of operating model may broaden choice for healthcare providers.
What about digital health?
The applicability of blockchain or Ethereum itself to digital health depends on both mapping value to the virtual currency, and mapping transactions into smart contracts.
At this stage, my view is that it’s definitely worth exploring the use cases, and trying to understand how they would work in practice. I’ve heard of interest in using it for wearables, federated analysis and data sharing.
Maybe use of my health data is worth something to clinical research (academic or industrial), and the blockchain is good way for me to manage consent records or share benefits.
My variant in the BRCA1 or KRAS genes, or my blood pressure and glucose meter values, may only be tiny data points for a large study. Researchers need a mechanism to compensate a lot of people with a small amount. At the same time, how can many participants automate engagement with many studies? That’s where this technology might help.
As with all health data sharing use cases, there are complexities in getting the information governance right, and second order effects to consider.
To some extent Ethereum helps anonymity, since the data transmitted can just be associated with a public identifier of which only I know the true identity.
Yet what does it mean for bias if one anonymous donor’s data is popular for many studies (because the public ledger shows higher than average value)?
What Ethereum or other platforms are unlikely to do is protect the payload of data once you’ve agreed to share. Other mechanisms would have to be brought in for that.
What it can do is help automate the process of ‘digital delivery’ by automating the ‘many to many’ steps of applying public key encryption of data.
Alternatively, our work in genomics tells me that there are large efforts underway to curate databases of known cases with genomic profiles, and to offer those cases to clinicians at a price.
It’s hard to meet the needs of the ‘long tail’ of medical specialty with a few database products, so a decentralised system of sharing cases might be more feasible. After all, clinicians are already highly networked in their field. It seems a more natural fit to traditional models of expertise, medical knowledge sharing.
Whatever the business models and smart contracts we devise, blockchain technologies are worth considering. The core concepts of trust, transparency and decentralisation map significantly on what is important to a lot of people in health and research.
Roderigo Barnes was one of the first employees of Aridhia Informatics, which is a clinical and transactional informatics company based in Scotland that was formed in 2007. He has been instrumental in designing its approach to big data and in developing its research analytics and stratified medicine services.