One evening in 2016, my 9-year-old son suggested we use Bitcoin to purchase something on the Microsoft Xbox store. Surprised by his suggestion, I was suddenly struck with two thoughts: 1) Microsoft, by accepting Bitcoin, was validating cryptocurrency as a credible form of payment, and 2) I was getting old. My 9-year-old seemed to have a better understanding of a new technology than I did, hardly the first time – or the last time – that happened. In spite of my initial feelings of defeat, I resolved not to cede victory to my son without a fight. I immediately set out to understand cryptocurrencies and, more importantly, the technology underpinning them known as blockchain.
Even just a few years ago, my ignorance of how blockchains work may have been acceptable, but it hardly seems acceptable now. Much more than just cryptocurrency, blockchain technology is beginning to affect every industry that values information sharing and security, and it is about to usher in a revolution in health care. But what are blockchains, and why are they so important?
Blockchains were first conceptualized almost 3 decades ago, but the invention of the first blockchain as we know it today occurred in 2008 by Satoshi Nakomoto, creator of Bitcoin. Blockchains can be thought of as a way to store and communicate information while ensuring its integrity and security. Admittedly, the technology can be a bit confusing, but we’ll attempt to simplify it by focusing on a few fundamental elements.
As the name indicates, the blockchain model relies on a chain of connected blocks. Each block contains some data (which can be financial, medical, legal, or anything else) and bears a unique fingerprint known as a “hash.” Each hash is different and depends entirely on the data stored in the block. In other words, if the contents of the block change, the hash changes, creating an entirely new fingerprint. Each block on the chain also keeps a record of the hash of the previous block. This “links” the chain together, and is the first key to its robust security: If any block is tampered with, its fingerprint will change and it will no longer be linked, thus invalidating all following blocks on the chain.
Ensuring the integrity of the blockchain doesn’t stop there. Just as actual fingerprints can be spoofed by enterprising criminals, hash technology isn’t enough to provide complete security. Thus, several other security features are built into blockchains, with the most noteworthy and important being “decentralization.” This means that blockchains are not stored on any single computer. On the contrary, duplicate copies of every blockchain exist on thousands of computers around the world, creating redundancy and minimizing the vulnerability that any single chain could be tampered with. Before any change in the blockchain can be made and accepted, it must be validated by a majority of the computers storing the chain.
If this all seems perplexing, that’s because it is. Blockchains are complex and difficult to visualize. (But if you’d like a deeper understanding, there are many great YouTube videos that do a great job explaining them.) For now, just remember this: Blockchains are very secure yet highly accessible, and will be essential to how data – especially health data – are stored and communicated in the future.