The blockchain comprises a digital network of blocks with a comprehensive ledger for transactions in a cryptocurrency such as Bitcoin or other altcoins.
One of the distinguishing features of the blockchain is that it is maintained across more than one computer.
The ledger can be public or private (with permission). In this sense, the blockchain is immune to data manipulation, which makes it not only open but also verifiable.
Since a blockchain is stored on a network of computers, it is very difficult to tamper with.
The Blockchain was originally invented by a person or group of people under the name Satoshi Nakamoto in 2008.
Originally, the blockchain was intended to serve as a public transaction ledger for Bitcoin, the world’s first cryptocurrency.
Specifically, bundles of transaction data called “blocks” are added to the ledger in chronological order, forming a “chain.”
These blocks contain things like the date, time, dollar amount, and (in some cases) the public addresses of the sender and receiver.
The computers responsible for maintaining a blockchain network are called “nodes.” These nodes perform the tasks necessary to confirm transactions and add them to the ledger.
In return for their work, nodes receive rewards in the form of crypto tokens.
Blockchain takes advantage of P2P data.
By storing data through a peer-to-peer (P2P) network, blockchain controls a variety of risks traditionally associated with centrally stored data.
Most notably, P2P blockchain networks have no centralized vulnerabilities. Consequently, hackers cannot exploit these networks in the normal way, nor does the network have a central point of failure.
To hack or modify the ledger of a blockchain, more than half of the nodes must be compromised.
Looking ahead, blockchain technology is an area of intense research across industries, including financial services and payments.