Blockchain...

 Blockchain!! Blockchain!!

We often here about Bitcoin in our daily life. but do we know enough about its foundation, that on which technology it's based on. that's why Todays, topic is about blockchain. The unsung hero behind every secure and legitimate transaction of Bitcoin and like every cryptocurrency.

Before diving into the core part of the Blog, let's see why we are in need of blockchain. so, take an example of our current financial system. suppose A paid $1000 to B then how this transaction reflects in baking software. A's account gets debited with $1000 whereas B's Account get credited with $1000, isn't it?? but here the issue is all the control of our transaction is in the hands of banks. They may put different amount instead of $1000. but they didn't because they are under scrutiny of central bank and central bank is under observation of finance ministry. it only means our whole financial system running on trust. hence our system is Centralized. to cop this issue up Satoshi Nakamoto introduced the world's first cryptocurrency Bitcoin. which based on Blockchain technology and having a decentralized system and this is one of the applications of blockchain for secure and peer to peer transaction with no intervention of third party between the two

let's go Step by step-

let's discuss about its birth. In 1991, two researchers "Stuart Haber" and "W. Scott Stornetta" wanted to implement the system where document timestamps could not be tampered with. but it was about two decades since its first application. i.e. by "Satoshi Nakamoto" the pseudonymous creator of Bitcoin. who first applied the technology of blockchain in his paperwork in 2008 namely "Bitcoin: A Peer-to-Peer Electronic Cash System".

Exactly, what is Blockchain??

The name itself suggests a definition of it that is the chain of blocks. then what is block, Block is the storehouse of the transaction data. Every block contains 3 elements Transaction data, Timestamp and Hashes. every block is connected with next block and formed a chain, so it called as blockchain.

Timestamp - Time at which data was validating.

Hashes - a unique cryptographic code created from the block's contents and the previous block's hash. This is the heroic element which prevent block from get tampering. Which we'll see in upcoming para.

Question arises how does it work??

Blockchain has its own database in which information gets stored and accessed. Once the transaction data is uploaded on the database then this database get distributed among the blockchains of the other network nodes (computer, laptop and other kind of devices). which means multiple copies are saved on many machines, and they must all match for it to be valid. this is important read it again.

Node: - A node is simply a system or device that runs the software of a specific blockchain.

This whole information is stored in block. once block get full, Block get encrypted with Hexadecimal code called "Hash".

Important question Why it seems to be secure and safe?

A block contains information about that transaction. so, anyone can tamper it, right?? 

It's a big NO...

here the hashes come to play its crucial role. as we discuss earlier that how hashes are form, it contains the information of block's content and hash code of previous block. and this hash becomes the block-header of next block. 

if someone tries to change the information in a block, its hash will change. Since each block also contains the previous block's hash, changing one block would require changing every subsequent block, which is practically impossible. as this change is done in single node i.e. device, other nodes don't accept this change, and the change get noticed and rejected. This is how hashing helps make blockchains secure.

Where can we use blockchain technology??

1. Cryptocurrency 

2. Alternative of banks.

3. Voting

4. Healthcare

And many more this is just overview...

Pro's: -

1. It has a secure network.

2. No intervention of third party. peer to peer transaction.

3. decentralization makes it secure.

4. Restriction of third party makes it cost effective.

5. Transparent technology.

Con's: - 

1. As bitcoin required to mine, it needs lot of electricity.

2. Significant technology cost.

3. Blockchain can be used for illicit activity such as dark web. but percentage is equal to less than 1%.

Bottom line: -

In short, a blockchain is a shared database. Bits of data are stored in blocks, and each network node has a replica of the entire database. Security is ensured since the majority of nodes will not accept a change if someone tries to edit or delete an entry in one copy of the ledger.