Introduction
In the early days of bitcoin (2008), the earliest forms of the blockchain software did not save all of the information necessary to recover the history of transactions and to produce mathematically secure proofs. Originally, each individual node was responsible for ensuring that it stored the current latest block of transactions and that it received new blocks from other nodes as they were produced. Because this task could take considerable time, a time-based replaceable snapshot mechanism was developed. This mechanism for handling updates led to the current blockchain structure.
Initial development
The invention of bitcoin dates back to 2008. https://mostbet-india-bangladesh.com/ It was invented by an unknown person using the name Satoshi Nakamoto, with some functionality dating back to 2008.[2][3][4] Nakamoto published the bitcoin whitepaper in 2008 and released the first version of the bitcoin software in 2009. The software was released under a license that allowed anyone to download it and use it for any purpose. The main topics treated in the paper included cryptography, economics, and computer network security.
By June 2012, the bitcoin blockchain had accumulated over 100,000 blocks, making it the largest blockchain by far and larger than the global payment system by total value. In November 2013, the number of bitcoins in circulation was estimated at 17 million.[5]
Architecture
A blockchain is a continuously growing list of records, called blocks, which are linked and secured using cryptography. Each block normally contains a hash pointer as a link to a previous block, a timestamp and transaction data. By design, a block cannot be changed once it has been added to the chain, which is an essential requirement for all distributed consensus systems. A related concept is that of a Merkle tree which is used to allow fast block validation and hashing. A block stores all transactions that have been validated and added to the blockchain. By design, this means that a block cannot be changed once it has been added, which is an essential property for a distributed database.[2]
Structure of a blockchain
Blockchain data structures: From top to bottom, left to right, this series of images shows the conceptual structure of the blockchain, including an arbitrary number of transactions. A simple blockchain might consist of a single block, whereas more complex blockchains could consist of several million blocks. These images show that the blockchain is a linear list of blocks. The differences between the various images is in the size of the blocks, the shaded region, the total number of transactions, and the visualization of transactions that belong to each block.