Definitions Matter when talking about Blockchain
There is lots of talk of bitcoin and blockchain in the news these days. It’s clear what bitcoin is, but the precise definition of a blockchain is more than a bit more elusive.
Definitions matter. In thermodynamics, you have a reasonable definition for temperature. But with that definition, it turns out that lasers have a negative temperature. To make things worse, negative temperatures are actually hotter than any positive temperature. In math, the Cantor function has a graph that is incredibly chopped up, but that badly chopped up graph turns out to actually be continuous. In math and science, these sorts of things are good. They make you think about things until you get to the precise definitions that you really want.
The data structure that bitcoin uses is probably a blockchain, although the term “blockchain” never actually appeared in the original bitcoin specification. The closest it came was a comment in the source code that talked about building a “chain of blocks.”
To find out what a blockchain is, I asked several people who I know who are currently working on blockchain projects exactly what is and what isn’t a blockchain.
The most common answer was that a blockchain is exactly what it takes to get funding for a blockchain project. People take whatever project they’re working, add the word “blockchain” to various budget documents, et voila, they have a blockchain project.
That wasn’t exactly the answer that I was looking for, so I asked a few more questions, and it turned out that the only two common elements of all blockchains were the fact that they used a distributed database of some sort, and that updates to that database were cryptographically linked to previous updates in some way.
The bitcoin blockchain certainly meets this definition. And it turns out that both open source version control systems Git and Subversion are blockchains by that definition. But then lasers have a negative temperature and the Cantor function is continuous.
But on the bright side, with that definition we can honestly say that blockchain technology is almost universal these days, even if the use of bitcoin isn’t.
About the Author
Luther Martin, Micro Focus Distinguished Technologist, is a frequent contributor to articles and blogs. Recent articles include The Security of Cryptography and the Wisdom of Crowds, in the ISSA Journal, The dangers of implementing blockchain technology in Information Age, and The Real Value of Bitcoin in the voltage.com blog.