eHealth and blockchain scalability: The Trilemma
It is impossible to look at eHealth and ignore the blockchain scalability challenge. Vitalik Buterin, the Ethereum founder, coined the term ‘trilemma’ referring to the triple practical challenge facing the fast developing blockchain technology. The challenges in question are decentralisation, security and scalability. All three are central components of the technology but, arguably, the degree of criticality varies depending on the nature of the project in question. For healthcare, all three appear to be equally critical. Let’s look at scalability.
There is no question that at this stage in the life of this technology, scalability remains a significant challenge. Blockchain’s append-only character is fundamental to the immutability of data and hence its provenance guarantee. In healthcare, a huge volume of data is generated, and this is non-stop. Take an example of England. Every 36 hours, 1 million people are attended to within the National Health Service (NHS) system. Many will generate just a handful of kilobytes of data. At the other end of the scale, some patients generate several gigabytes of data from a single episode of interacting with the health services.
It all adds up to a relentless build-up of a huge amount of data. If there was to be a nationwide or conceivably and ideally, transnational blockchain electronic health record system, in the same way that enterprises like Visa or Mastercard are, it would have to be able to cope with that volume of data and that data will be growing apace each minute of every day. The reality of blockchain is that, as data is added; and healthcare is one of the most data intensive industries, more blocks are added. This translates into increased time in the processing of each transaction. With that, a scenario where the whole system is creaking to a point of being unfit for purpose is conceivable. eHealth on a blockchain platform is inconceivable without addressing the scalability question.
eHealth and blockchain scalability: The scale of the challenge
One has to look at the leading cryptos to start understanding the scale of the challenge. Bitcoin has a transactions per second (tps) rate of 7. Ethereum’s tps is better but still at 15, it is light years away from Visa’s 24,000. However, the industry is tackling this challenge and a number of cryptocurrencies have already achieved a tps in four figures. An example is Stellar Lumens (XLM) with a 1000 tps. This is one factor that has been responsible for Stellar’s popularity as a platform among those creating and marketing distributed Applications (dApps).
Both Bitcoin and Ethereum have moved to address the slow throughput challenge. The former through what is termed as a ‘Layer 2’ solution, also called the ‘Lightening Network’. For Ethereum, similar efforts are at an advanced stage including Plasma and Raiden Network projects. These are off-chain solutions.
With all the various projects going on with different cryptocurrencies, sharding is seen by many to be one with the greatest potential to address the scalability problem. Of course, sharding is a concept that is not exclusive to blockchain. It is in fact widely used in computer databases where a large database is partitioned into smaller ‘data shards’ which are faster and easier to manage. In blockchains, it is envisaged that the higher the number of network shards with the resultant parallel processing, the speedier the transactions. Sharding has a real promise in this area but there a number of difficult questions with this approach that need to be solved.
Enterprise thrives on challenge. Identify a problem and the race is on to find a solution. eHealth and blockchain scalability falls neatly in this category. The promise of blockchain is immense but the ‘trilemma’ has got to be addressed if that promise is to be realised. Predictably, this challenge has triggered fierce competition in the blockchain sphere in a bid to find a solution and there are a number of very promising developments.
Successful deployment of blockchain in healthcare hinges on finding effective solutions in all three areas. With healthcare being so data intensive, it is certainly an area that is set to benefit from a successful solution to the blockchain scalability challenge and one that does so without compromising on the other two i.e. decentralisation and security.