What is the history of blockchain technology?

The idea behind blockchain technology was described as early as 1991 when research scientists Stuart Haber and W. Scott Stornetta introduced a computationally practical solution for time-stamping digital documents so that they could not be backdated or tampered with.

The underlying technology behind cryptocurrencies is the blockchain. It allows every client in the network to reach consensus without ever having to trust each other.

Blockchain was invented by a person (or group of people) using the name Satoshi Nakamoto in 2008 to serve as the public transaction ledger of the cryptocurrency bitcoin.The identity of Satoshi Nakamoto is unknown. The invention of the blockchain for bitcoin made it the first digital currency to solve the double-spending problem without the need of a trusted authority or central server. The bitcoin design has inspired other applications,and blockchains that are readable by the public are widely used by cryptocurrencies. Blockchain is considered a type of payment rail. Private blockchains have been proposed for business use. Sources such as Computerworld called the marketing of such blockchains without a proper security model "snake oil".

In August 2014, the bitcoin blockchain file size, containing records of all transactions that have occurred on the network, reached 20 GB (gigabytes).In January 2015, the size had grown to almost 30 GB, and from January 2016 to January 2017, the bitcoin blockchain grew from 50 GB to 100 GB in size.

The words block and chain were used separately in Satoshi Nakamoto's original paper but were eventually popularized as a single word, blockchain, by 2016.

A blockchain consists of a linear chain of multiple linked blocks that are cryptographically secured. Each block is a file made up of multiple components. It contains, among other things, a list of recent transactions and a reference to the block that came immediately before it. Each validated block also contains a registered solution (block hash) of a complex mathematical problem, which is part of the process of Mining.

A futuristic and quite visionary technology as believed by most, blockchain as a technology promotes transparency and empowers people to think differently about exchanging value and assets, sharing data, doing business and enforcing contracts. It is transforming the digital information ecosystem with respect to data collection and preservation. Also known as public ledger of transaction, blockchain is a shared technology administered in a shared network of computers, rather than resting with a single provider. Data can now be shared across multiple organizations enabling business processes to eliminate scope for frauds while also create new revenue opportunities.

Blockchain technology may also be applied in other activities that do not necessarily involve financial operations, but in the context of cryptocurrencies, they are responsible for keeping a permanent record of all confirmed transactions, working as a decentralized, distributed and public digital ledger.

Simply put, a blockchain is an endless growing list of data records (chain of blocks) that is secured by cryptography and highly resistant to modification