Читать книгу Bitcoin, Blockchain & Co. - Joe Martin - Страница 18

On the one hand, a blockchain consists of cryptographically connected data blocks in which the individual transactions of system participants are recorded. That is where the name “blockchain” comes from. A blockchain itself is relatively worthless because it is not safe in and of itself. The security is achieved by various measures. The single most important thing about this is that the chain is distributed over as many computers (nodes) as possible at the same time. Only this can make a blockchain secure, because if data is changed on only one part of the nodes, this change will sooner or later get overwritten and the data on the majority of the nodes becomes the truth. The truth then gets synchronized. The rules for maintaining this truth are also called the “Consensus Algorithm.”

This consensus algorithm must of course also be known to the nodes, just as with any other specifications they must adhere to. Software must basically run on every node to get that node to work at all. For all intents and purposes, that’s the node application. And this raises the interesting question . . . what software?

It was very easy to answer this question in 2009 because there was only one version—Nakamoto’s. Of course, the software was far from error-free. Actually, all software is. Working with other programmers, these errors were gradually eliminated. After every significant change in the code, the nodes were bought up to date with the latest version, so that all nodes ran on the same software. It was, and still is, called “Bitcoin Core.”