BLOCKCHAIN WITH SIMPLE EXAMPLES.

       Blockchain is one of the latest technology that has the potential to bring about huge changes in the economy of 21th century. So let's we start it in very simple language .You can talk directly to your friend with a mobile phone . But if you want to buy something online on this mobile phone so you need a middleman , who can guarantee the seller that you have given the money. But is it possible for the buyer and seller to negotiate directly without the help of middleman ?  A new Technology called 'BLOCKCHAIN' is making this possible. 

       Blockchain can be considered as a distributed database which is copied on thousands of computers , not on two computers. Blockchain computer describes the entire history of each record . This database is encrypted i.e every single record has been recorded in a confidential manner. There is also a blockchain fault tolerance i.e even if some computers in this system go bad even then the system continues to function properly . Blockchain database is a public ledger . In which any record needs a lot of acceptance to be recorded . It is very difficult to hack because to do this , hackers will have to hack thousands of computers once. This is the reason why we consider blockchain as a secure technology. 

     Blockchain was first used in 2008 , when a digital currency called a BITCOIN was invented. Bitcoin is not a physical currency that can be touched . The purpose of bidcoin was to remove the 3rd party in transaction process. It allows a online payment between seller and buyer directly. Bidcoin has no owner or authority or agency to control. "BIDCOIN IS AN INNOVATIVE PAYMENT NETWORK AND A NEW KIND OF MONEY ".

    Blockchain not only for the purpose of money or currency but it can be used anywhere where traditionally trust is a middleman needed to guarantee and trust such as all the transactions that the notary public or government institution has to confirm today.Take a simple example : Suppose we assure that you are buying  house. You will want this transaction to be recorded by the government registrar . So that you get a government document which proves that you are the legal owner of that house. The public registrar is only giving evidence of the deal. And there is a possibility that the work of public registrar will be done by Blockchain in near future. Because the transaction recorded in blockchain will have as much recognition as the registry certificate today. Due to blockchain being a public document it will be less likely to be consumed.

      The use of blockchain technology has many more possible examples . Like under any government scheme if a poor man has to get a salary with blockchain technology , he an be given that amount directly on his mobile phone or if people suffering from a natural disaster have to pay the loss so their support amount can be given directly on their mobilephone. This will also reduce corruption. Blockchain cm also be used in education. In lieu of paper degree , blockchain based degree may be awarded to students. This can also solve the problem of fake degrees. 

BENEFITS AND CHALLENGES OF BLOCKCHAIN : 

BENEFITS : 

1. DECENTRALIZED AND TRUSTLESS : Blockchain is a public Leger of all transactions on the network which is maintained by different decentralized nodes. Blockchain technology enables a decentralized and trust less peer to peer network where the peer do not need a trusted intermediary interacting with each other. Since a block chain network is not controlled by a central authority and all the transactions are verified and validated by a consensus among the peers , the peers do not need to trust each other.

2. RESILIENT : Blockchain network is resilient to failure . It is a decentralized peer to peer network with no single point of failure. The blockchain itself is an immutable and durable ledger and the transactions once recorded on the block chain after a consensus among the peers cannot be altered or deleted. 

3. SCALABLE :  blockchain network is highly scalable in nature as it is maintained by a network of peers. The computing capability of the network scales up as more and more peers join the network. 

4. SECURE AND AUDITABLE : All the transactions in a blockchain network are secured by strong cryptography . Furthermore , the transparent nature of the public ledger maintained by blockchain network make it secure and auditable as everyone on the network knows about all the transaction and the transactions cannot be disputed. 

5. AUTONOMOUS : blockchain can enable different entities to communicate with each other and do transaction autonomously . For example an IoT devices. 

CHALLENGES :

1. CAP AND BLOCKCHAIN : For distributed data systems , a trade off exists between consistency and availability . These trade off are explained with the CAP Theorem, which states that under partitioning , a distributed data system can either be consistent or available but not both at the same time.

          Blockchain gives upon consistency to be available and partition tolerant . Blockchain is a distributed ledger which is eventually consistent i.e all nodes eventually see the same ledger.

2. SMART CONTRACT VULNERABILITIES : Smart contract can have software vulnerabilities which can be exploited by hackers 

3. AWARENESS : Blockchain is a nascent technology and is mostly adopted in the financial sector. 

4. EFFICIENCY : Since all the nodes in a blockchain network perform the same computations in an attempt to mine the next block for the blockchain this is not an efficient approach.