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Basic knowledge of blockchain

Basic knowledge of blockchain that is super easy to understand

The blockchain technology that we often hear about these days has the potential to be described as "technological innovation since the Internet." What kind of technology is blockchain? Even if I look it up with that in mind, many of them are explained in the context of Bitcoin and virtual currencies, and the question "What is blockchain after all?" Is hard to solve. This time, I created this article with the aim of explaining what a blockchain is like in the most polite and easy-to-understand manner on the Internet so that you can get a rough idea of ​​what it is. I'm trying to explain the technical things as much as possible, so by the time I finish reading, I think that non-engineer readers will have an overview of blockchain.

What is a blockchain?

What is blockchain? "Even if some of the participants are fraudulent or do not work properly, they can make correct transactions, it is very difficult to tamper with, they do not stop, and the same data is distributed and retained by many participants. It is a mechanism to make it.

If you dare to summarize it in one word without fear of misunderstanding, blockchain is such a mechanism. However, even at this time (April 2018), the definition of blockchain has not been decided, and the term is used in various interpretations depending on the time and case. In Japan, the following definitions published by the Japan Blockchain Association in October 2016 are frequently referred to, and the above is also an easy-to-understand paraphrase.

Features of blockchain

The features of the blockchain can be narrowed down to the following four points.
・ Very difficult to tamper with
・ System down does not occur
・ Transaction records cannot be erased
・ Autonomous decentralized system

The blockchain has a mechanism that can easily detect falsification of data by using the cryptographic techniques such as "hash" and "electronic signature" explained in Chapter 4, "Mechanism of blockchain". Also, in the blockchain, an unspecified number of participants make transactions, but some computers go down because many participants (not all participants) record a copy of the transaction history of all participants. However, the entire system will not go down as the remaining large number of participants will continue to hold records. Since this copy of the transaction history cannot be deleted, the transaction record once recorded will not be erased and will remain as evidence. A system in which data is distributed among many participants is called a distributed system.

In many distributed systems up to now, there was a central administrator for the system. However, in the blockchain, all participants continue to copy transaction history autonomously. This is called an autonomous decentralized system and can be said to be one of the major features of blockchain. The characteristics of this autonomous decentralized system, which does not allow fraud or tampering and keeps a stable record of fair transaction history, were indispensable for transactions that require high creditworthiness, such as virtual currencies.

Difference between blockchain and database

If you read the explanation so far, you may feel that "blockchain is not so different from cloud database?" It's half right and half wrong.

Certainly, the cloud database is distributed across multiple computers and is backed up so that errors and tampering can be repaired. In addition, it can be said that the stability is high if it is a major service. However, the mechanism is centralized and requires the presence of an administrator to provide the service. If the administrator stops the service, the contents of the database will be lost, and the data may be deleted at the convenience of the administrator. Also, if the administrator is malicious, the contents of the data will be tampered with.

On the other hand, the blockchain cannot tamper with or delete the recorded data even if it is a service provider, and the participants cannot delete their own transaction history. This is the biggest difference between blockchain and databases. Because of this characteristic, it can be said that even an unnamed service provider with low creditworthiness can entrust transactions such as currency.

Relationship between blockchain and virtual currency

I think you can understand that blockchain is used for currency transactions because it is safe and secure, but let's review the background of the birth of blockchain once.

In the first place, blockchain has appeared in the world as a technology to support Bitcoin, whose concept was announced in 2008 and transactions started in 2009. It is a technological innovation by combining existing technologies brought about by Mr. Satoshi Nakamoto, who is said to be the creator of Bitcoin and blockchain .

Satoshi Nakamoto is said to have hated the government's repeated intervention in the economy and created Bitcoin to create a new infrastructure where no one could intervene, never go down, and record transactions fairly. There is. And the technology that became the foundation was the blockchain.