Bitcoin hit news headlines this week as the price of one unit of the cryptocurrency passed $11,500 for the first time.
1998 – 2009 The pre-Bitcoin years
Although Bitcoin was the first established cryptocurrency, there had been previous attempts at creating online currencies with ledgers secured by encryption. Two examples of these were B-Money and Bit Gold, which were formulated but never fully developed.
Blockchain---
The validity of each cryptocurrency's coins is provided by a blockchain. A blockchain is a continuously growing list of records, called blocks, which are linked and secured using cryptography.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. Each block typically contains a hash pointer as a link to a previous block a timestamp and transaction data. By design, blockchains are inherently resistant to modification of the data. It is an open, distributed ledger that can record transactions between two parties efficiently and in a verifiable and permanent way.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.