Hello Blockchain !

In October 2008, Nakamoto published a paper describing the bitcoin digital currency. It was titled “Bitcoin: A Peer-to-Peer Electronic Cash System“. Three months later, Nakamoto released the version 0.1 of bitcoin software that launched the network and the first units of the bitcoin cryptocurrency.
As part of the implementation, Nakamoto also devised the first blockchain database, which was instrumental be first in solving the double-spending problem for digital currency.

A blockchain is a continuously growing list of records, called blocks, which are linked and secured using cryptography. Each block typically contains a cryptographic hash of the previous block, a timestamp and transaction data. By design, a blockchain is inherently resistant to modification of the data.
For use as a distributed ledger, a blockchain is typically managed by a peer-to-peer network collectively adhering to a protocol for validating new blocks. Once recorded, the data in any given block cannot be altered retroactively without the alteration of all subsequent blocks, which requires collusion of the network majority. Therefore it can be used for transactions between two parties efficiently and in a verifiable and permanent way.