When it comes to Blockchain, a lot of people- especially people hearing about it for the first time, wonder what it is, how it works, how did it come about, and what can be done with it. Many only know about Blockchain with regards to the development aspect of it, but contrary to popular opinion, beliefs, and knowledge, Blockchain is a lot more. What, then, is the Blockchain technology?

Blockchain technology can simply be defined as an arrangement (or a group of arrangement) of unchangeable data, that are time-stamped, stored and managed by a group or group of computers in a decentralised manner. This technology stores data securely, through cryptography, in blocks that are connected to each other.

Cryptography is a method of writing or reading coded messages. The word is derived from two words “crypto” which means “secret” and “graphy” which means “writing”. Bringing this two words together, “crypto-graphy” will simply mean “secret writing”.

Though Blockchain has been around for a while, SATOSHI NAKAMOTO, a person or a group of persons, is believed to have invented this technology called the Bitcoin Blockchain, which allows digital information to be distributed amongst peers. No one can identify who this person or group is, but the history of this technology cannot be completely told without he, she or they being spoken of.

The uniqueness of this technology and the spread of its evangelism are a result of several factors.• Its decentralised nature. Unlike the centralised nature of a lot of things in our world today, Blockchain technology has no central authority. Its data are distributed and stored with several computers owned by different individuals.• It is immutable. Data stored using Blockchain cannot be changed or falsified.• Blockchain technology is open and transparent.• The uniqueness of this technology also includes the fact that it carries no transactional cost, thereby eliminating the option or thought of the middleman, and enabling peer-to-peer transactions.• It also stores all forms of data - videos, music, ebooks, special records et al as blocks of data, and stores them in the cloud.• This technology works through the aid of a network of thousands (or millions as the case may be) of computers which regularly updates these chains of blocks after having validated that the data received are true and valid.

Blockchain uses a function called the cryptographic hash function to encode, secure, and validate already stored data in blocks. It gives one a certain fixed length of hash output for every length of data input. A great example of this is the bitcoin Blockchain which uses the SHA-256 (Secure Hashing Algorithm with 256-bits in length) cryptographic hashing function.

To answer the questions of how this technology is sustained, one would have to understand how the technology works. Since there is no autonomous centralised authority, the Blockchain technology is maintained through its peer-to-peer interactions. This tech is a chain of interconnected computers known as nodes which are owned by lots of individuals who store Blockchain data on their computers. Since these individuals have the same distributed data of the same Blockchain, it would become so difficult to tamper with a particular block successfully. To effectively do this, one would have to identify all nodes and change the data on that exact block in all the identified nodes with access to that data. This, of course, is an impossible task.

Blockchains are not all open to the general public. There are two types of Blockchains - the permissioned Blockchain and the public permissioned Blockchain. A public permissioned Blockchain is an open Blockchain in which anyone can see and participate in its network protocol and help maintain its consensus. This kind of Blockchain aren’t always desirable by organisations due to its open and transparent nature. This is where the privacy comes in.

A private permissioned Blockchain, or permissioned Blockchain, are Blockchain s that are only accessible to a certain selected number of nodes and from these selected nodes a few are appointed to administratively manage its Blockchain system.

Blockchain can be used for several things such as crowdfunding, forms or data management, auditing supply chains, elections, protecting properties and creating of smart contracts.