Academy (NDA) where they undergo rigorous training and are toughened to withstand extreme conditions. This indeed is one of the most disciplined industries of all. This industry’s peculiar feature is the intelligence service, who serves to keep a close watch on the activities in and around the country, they also keep a close watch on the happenings of their rival countries to ensure that if there happens to be any threat to their country, they’re sufficiently prepared to counteract. India has the world’s third largest defence budget which enables it to equip itself with aircrafts and other machinery that are par above other countries.
1.2.6 IT Industry
IT industry stands for Information and technology industry [2]. IT sector has been majorly responsible for transforming India into a global economy since we have received multiple outsourced and mediated technology-based work contracts. These are the companies that provide us with computing solutions as well as other hardware and software applications such as Intel, Hcl, and Apple. Utilization of computers for storage, transmission, manipulation and retrieval of data or information is the basis of this type of industry. This sector has gained advancement and has enlarged considerably in our country over the last few years, generating employment for a huge chunk of the population and also contributing to the country’s overall economy. The major IT hubs in India are Bangalore, Chennai, Noida, and Hyderabad. The initial wave of the IT industry that we see today was first established when the government set up the Software Technology Parks of India (STPI) in the early 90s. Let us consider a day-to-day life scenario as an example to understand the services and features of the IT industry. So, consider that a person is facing trouble with the signal strength on his mobile device. He will convey his problem to the customer care service that the network company offers. They will then work toward tracing the cause of inconvenience, if it is a faulty sim card or a trouble with the signal tower of that area and then work for providing a solution at the earliest possible. Network provider is one type of industry that comes under the IT sector; many such companies exist under this sector functioning under the umbrella of information and technology.
1.3 What is Blockchain?
In layman’s language we may understand it as a chain of blocks containing information as illustrated in Figure 1.2. The original purpose of blockchain was to time stamp documents however it did not find much application [3]. The blockchain majorly picked up popularity when it was adapted to create a digital cryptocurrency—Bitcoin, by Satoshi Nakamoto in 2009. The most prominent feature of blockchain is that once any information is entered, it is nearly impossible to edit or delete it. Each block in a blockchain has three components associated to it, which are data, hash, and hash of the previous block. The data of a block contains information relevant to the purpose which the chain is utilized for. The next component, i.e., hash is like the finger print of the block and is thus unique to every block. The hash of a block is calculated after the data in entered. Therefore, if the content of any block is tampered with, it, in turn, changes the hash, and hence, it is no longer the same block, and this feature particularly allows us to ensure that any information once entered in a blockchain cannot be modified or deleted. The third component of a block is the hash of the previous block. Each block contains the hash of the previous block which enables the chain formation. If any block in this chain is modified, its hash changes, hence breaking the linkage through the entire length of the chain, disrupting the entire chain formation. This is how the safety and integrity of any blockchain is ensured. The first block of a blockchain is referred to as genesis block.
Figure 1.2 Illustration of blockchain technology.
Let us now understand how blockchain ensures a high level of security. Firstly, since each block contains the hash of the previous block, it is not possible to modify the content of any block without disrupting the chain henceforth. Secondly, this technology follows a practice called proof of work. Hashes are insufficient to ensure protection because computers these days are fast enough to recalculate all the hashes of the blocks within seconds; this is where proof of work comes into the picture. Through this method, we considerably increase the time required to calculate the hash of a single block. These two features when put together enhance the security mechanism. Thirdly, the entire blockchain in available to all its users; in other words, we may say that a blockchain is distributed. This peer-to-peer network enables all members to receive any new block that is formed; it is then verified by each node and is given consensus, only then it is incorporated into the chain. So, in case a block comes up that is tampered with it will be rejected be the other nodes [4]. The benefits of this architecture as observed are tamper-proof nature and better traceability along with resolving trust issues that may otherwise interrupt the supply chain [5]. Blockchain can fall under two categories private and public. A public blockchain is a completely transparent ledger and is decentralized. The information in this platform is encrypted and can be accessed on multiple devices. A public blockchain is nearly impossible to hack, as that will require acceptance from at least 51% of the nodes which is very difficult to attain for a malicious task, as the total number of nodes connected to this chain is very large. In contrast, a private blockchain has a limited audience that can access the content stored on the blockchain. It is an invitation only blockchain and is under the control of a single entity, hence not decentralized. A public blockchain is comparatively more secure than a private one.
Although every user in the network has access to all the blocks, not complete knowledge of any transaction or activity may be gained by all users. The details of all transactions are encrypted. For examples, if user A buys apples from user B via this network, the other users can know that there has been a transaction but would not attain all details, i.e., they may know that there has been a transaction but may not know that is was held for the exchange of apples. Most of the platforms or services that we use today be it Facebook or Google are centralized in nature and they have a lot of control in terms of privacy, and you may not be willing to give any one entity access to all your data. So, blockchain technology overcomes this concern where no one node or entity can have monotonous control or access to any piece of information.
The most common application of blockchain is seen in the cryptographic currency of Bitcoin. Cryptocurrency is a completely digital form of money. A distinctive feature of transaction with Bitcoins is that there is no requirement for a mediating institution. A conventional electronic payment involves third party other than the buyer and seller, usually a bank that facilitates the transfer of money. This technology of Bitcoin eliminates the need of any such mediation. Also, the Bitcoins are decentralized which implies that their distribution and circulation globally can be monitored by a government or any similar organisation. Whenever a bitcoin transaction occurs, the blockchain records the sender’s and receiver’s Bitcoin addresses along with the amount. Each transaction is encrypted with public key cryptography and verified by multiple nodes; these transactions cannot be tampered with. The computers than individuals connect onto this network are referred to as bitcoin miners. The cost of entering into the Bitcoin network is fairly high and bitcoins can only be profitably mined using specialized devices. As the number of nodes in the network increases the difficulty of mining generally increases. What attracts people to bitcoins is to keep their money safe in a bitcoin network as compared to any bank. Some people see it as an investment but there happens to be lot of risk but it is claimed that by 2040 this network will be very well established. Even though we presently seem to observe bitcoins as the only major application of blockchain, a lot of scope beholds for this technology some aspects of which we will be coming across through the course of this chapter [6].
Another growing application of blockchain is the Smart contract. The purpose of smart contract resembles just what a usual contract does i.e., beholds conditions, clauses and agreements. The only difference is that here they are stored as a few lines of code that is kept safe inside a blockchain. Also, this technology allows two parties to bind
