Figure 1.8: Blockchain or a linked chain of blocks

Thus, the integrity of the data is maintained and the data once added

can be considered as tamper-proof. Please note that the nonce or

“number only used once” is a randomly generated number for each

block and is mostly used in cryptographic communication and

information technology.

1.6.1 Mining

We all know that Blockchain is a distributed ledger with more than

one owner. Now saying so, the following questions come up:

How the transactions would be validated?

Which among the owners would be responsible to validate the

transactions?

Even if some of the owners agree to do the job, what would

they gain from such an intensive process?

Well, the answer is that all the Blockchains have a decentralized

consensus process to validate the transactions where all or more

than one parties get involved. For the Bitcoin network, the owner of

the nodes themselves participate to earn a fraction of the token. So,

mining is a process of the validation of transactions, adding them to

the ledger, and confirming the same to the rest of the nodes in the

network. Mining is intentionally designed to be resource-intensive

and difficult, so that the number of blocks found each day by the

miners remains steady and the spam attacks could be controlled.

So, mining serves the following two purposes: