Yesterday I talked about what a block was, and I made a slight reference to what the blocks from; a block chain. But what is a block chain? That is a question I hope to answer; as well as provide some history and what the blockchain makes possible.
What is a Blockchain?
The blockchain is a ledger containing the records of all transactions; secured through cryptography, within blocks. And the link between each block is connected with the hash; a mathematical equation. The hash serves as a direct link that will lead to the previous block. Connecting the two blocks and becoming the newest parts of the chain. This data is saved and unable to be changed.
Why? Because the hash will only link to the original data. Any change would create a new chain and not being part of the original chain, and would be invalid data and unable to be excepted. If the new chain were to be accepted, every following block would also need to be added to the altered block. *An example of this is how Bitcoin Cash utilize the same exact chain. The creator of the current block server was Satoshi Nakamoto in 2008. And a year later bitcoin adopted the system.
A blockchain into the past
As I said earlier the blockchain based on cryptography. Cryptography was idealized by Stuart Haber and W. Scott Stornetta in 1991. The idea was solidified by the instruction of the Merkle tree; and in 2008 Satoshi Nakamoto used this idea to help validate the cryptocurrency Bitcoin. The Bitcoin blockchain reached 20 gigabytes in August of 2014, and by January 2015 it increase 150% to 30 gigabytes. By January in 2017 the Bitcoin blockchain had reached 100 gigabytes.
Every gigabyte is made up of 1,024 megabytes. And with every block in the blockchain being worth 1 megabyte, we can see the number of total blocks of contained within the block chain by the start of 2017; 102,400 blocks. When the miners solve the equation; linking with the hash, the miner gather 12.5 bitcoins. And after multiplying the total blocks by the bitcoins gathered, we find that there were 1.28 million bitcoins in circulation during January of 2017.