Blockchain technology
Blockchain is a procedure of information stockpiling in a decentralized way which implies there will be no central authority that can handle the information/data.
What is Central authority ?
As I live in Pakistan I will give an example of Pakistani Rupee ( PKR ) suppose I have a note of 1000rs which is printed by the state bank of Pakistan and the state bank of Pakistan ensures that this note of 1000rs esteemed as 1000rs not more or less so that determines that the state bank of Pakistan is the central authority of PKR everywhere on the world.
It relies upon the state bank of Pakistan that how much cash it will print or value the notes and coins of PKR.
On the other hand currencies like Bitcoin are decentralized so there is no central organization that can handle Bitcoin. This is on the grounds that Bitcoin depends on the blockchain and blockchain is the technology that decentralizes Bitcoin.
Decentralization
A big reason for blockchain to be secure is decentralization.
Blockchain is not present in a single computer Rather its present in a network of computers instead of one central authority, it is managed
And run by a network of computers collectively.
if someone wants to alter or do fraud in the blockchain one would need the majority of 51% of the computers present in the blockchain if someone manages to hijack 51% of the computers connected to the blockchain then fraud can be done but realistically hijacking 51% of the computers connected to the network is next to impossible because all of them are decentralized, not connected to a central authority that if you manage to hack one computer you will hack all of them. Someone will have to hijack every single computer at their locations and in a large blockchain like Bitcoins where millions of computers from all over the world are connected to the network there, it is almost impossible.
Nods And Miners
The people who are connected to the blockchain through a computer and those who allow the blockchain to run on their computers are known as nods some does among them are miners.
Whenever new data is added into the blockchain, it's the work of miners to verify that the person adding the data is done it properly or not or whether it's an attempt of data tampering.
You might wonder, what a computer gets that work 24*7 to verify which block is authentic and which is not, there must be some reward for it right
There is a reward my friends in the bitcoin blockchain the reward is in the form of Bitcoin.
Parts Of A Block In The Blockchain
Another reason for blockchain technology is that there are so many ways of data/information storage like we can store data/information in our computers in Excel let's say. In an Excel file, your data/info is stored structured in a form of a table same like that the data/info in the blockchain technology is structured like a block. Every block is made up of 3 main things
1- Data/information you will put in the block
2- Every block consists of a fingerprint that is called the Hash ( this is the way of uniquely identifying the block from the others. )
3- Hash of the previous box. Every block stores the fingerprint of the previous block.
This is how a block is linked to all other blocks in the blockchain technology and the main thing is that if you try to change a data/info present in a block because of that the hash in a block will change if the hash in one block is changing the hash in the other blocks will also change and that will ruin all the chain and that is the reason that tempering the data in blockchain technology is next to impossible.
Privacy Of The blockchain technology
No need for central authority anyone can view and verify using the public ledger. Any computers connected to the blockchain can see the data added to the block.
You might wonder again that if every connected computer to the blockchain can see the additional information in the blockchain so what about privacy?
The information in the blockchain is not only secure but also privacy protected because each computer in the network has its private key and a public key.
Private Key
Private Is used to both encrypt and decrypt the data and is shared between the sender and receiver of encrypted data.
Public key
Public key is only used to encrypt data and to decrypt the data,
So no other information will be revealed.