What is blockchain?

If you have been looking at crypto currencies lately, the term “blockchain” has probably popped up here and there. But what exactly is a blockchain and how does it work?

 Is it:

1. An insult

2. A piece of snazzy jewelry

3. A decentralized immutable
public database

4. A great way to get in shape

If you thought number 1, 2 or 4, then you must have had some weird conversations.

A blockchain, in short, is number 3. A decentralized database were the data cannot be changed. Put simply, the block is were the data is stored and the chain is the link between blocks. Due to its immutable and decentralized behaviour, a blockchain is made public so anyone can view it but cannot modify it. The data that is usually stored are transactions of crypto currencies. A blockchain in terms of crypto currency, basically acts as an immutable ledger. Some of these terms may seem confusing but I will explain them in sections.

Decentralized

For a blockchain to be decentralized, multiple nodes (computers that host the blockchain) all connect to the same network and run the blockchain simultaneously. All nodes on this network continuously validate each other to assure that no blocks of data have been tampered with and that each node has a copy of the same blockchain. If a blockchain is modified, the rest of the nodes tell the node with the mutated blockchain that it is wrong. The tampered with node then copies the blockchain on the other nodes and replaces its blockchain with the correct copy. This makes it near impossible for the blockchain to be tampered with. In contrast, a centralized database would only have one node. This means if someone tampers with the database, there may be no way to know or to stop it from happening.

Immutable

Immutable means that it cannot be changed. So any data that is in a blockchain, is there to stay. But how does a blockchain achieve this? Simply, because of its hash value.

A hash is made by using the sha256 encryption algorithm on a block in the blockchain. This algorithm is used by the us government to secure important information and documents and it is quite literally impossible to break. The hash value created is based on the data that it is encrypting, so the data inside the block. The hash value is stored on the block and acts as an address for another block to see. Every block has an address and the address of the next block in the blockchain. This creates the link between the blocks and is why the blockchain is considered a chain.

But how does this make it immutable?

Say you change the data in a block called block A and the block that contains block A’s address is block B. Because you changed its data it creates a new hash for its address. Because the address of block A is now different, block B no longer links to block A because block B contains the original hash of block A’s data. This renders every block past block B unavailable, including block A. When the other nodes see that this blockchain no longer has the same blocks they force the mutated blockchain to copy the correct version.

Final notes

Blockchain is still a new technology so there is still much work to be done in the development of these databases. New ideas come to fruition everyday and more companies are attempting to create their own blockchains and decentralized networks. I personally am amazed by this technology because of its decentralized nature and what it means for crypto currency’s. I can’t wait to see how much further blockchain technology goes in the next couple years.

This tech boom is starting to look good with much more to come from this centuries roaring twenties.

Thank you for your time and I wish you all the best.

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