Explained | What is blockchain technology?

blockchain
Distributed ledger technology is a digital system for recording the transaction of blocks in which the blocks are recorded in multiple places at the same time. Photo: AFP

• The Ministry of Electronics and Information Technology (MeitY) launched ‘Vishvasya-Blockchain Technology Stack’ to offer blockchain-as-a-service (BaaS) with a geographically distributed infrastructure designed to support various permissioned blockchain-based applications.

• The Technology Stack is hosted on geographically distributed infrastructure at NIC Data centers in Bhubaneswar, Pune and Hyderabad.

• With the vision to create trusted digital platforms, the government initiated National Blockchain Framework for promoting research and application development; facilitating state of the art, transparent, secure and trusted digital service delivery to citizens.

• The National Blockchain Framework would play an important role in enabling security, trust and transparency for various citizen-centric applications.

• The ministry also unveiled the NBFLite-Lightweight Blockchain Platform, Praamaanik and National Blockchain Portal.

What is blockchain technology?

• Blockchain is an innovative distributed ledger technology which was first introduced in the design and development of cryptocurrency — Bitcoin — in 2009.

• Distributed ledger technology is a digital system for recording the transaction of blocks in which the blocks are recorded in multiple places at the same time. The distributed ledger the data is replicated to multiple nodes and all nodes maintain the same data. 

• Distributed ledger technology is an umbrella term used to describe technologies which store, distribute and facilitate the exchange of value between users, either privately or publicly. Blockchain is one type of distributed ledger technology.

• In blockchain technology, when a transaction occurs, it is broadcast to all computers on the network. A set of new transactions, called a block, are authenticated by an agreed consensus mechanism, and then the validated transaction block is added to the previous chain of blocks. Every block is linked to the previous block, making double spending difficult because it would involve changing every subsequent block. 

• Blockchain enables a layer of trust and eliminates the need for a third party to validate the transactions. 

• Blockchain technology is an amalgamation of various technologies such as distributed systems, cryptography, etc.

• Each block contains details of transactions, hash of the previous block, timestamp, etc. 

• It is difficult for an adversary to modify the stored details at majority points. Therefore, Blockchain provides better security when compared with a centralised system.

• Data and transactions executed over the network are stored in the ledger in a decentralised manner over peer-to-peer network. Transactions are validated and verified through consensus (consensus protocols) across nodes of the blockchain network.

• Blockchain can be used in both permissioned and permissionless models. These models have applications in various domains such as education, governance, finance & banking, healthcare, logistics, cybersecurity, media, legal, power sector, etc.

• Globally and nationally, various efforts are being made towards implementing blockchain-based applications. Many countries have recognised the potential of blockchain technology and are trying to become the global pioneers.

Key features of blockchain:

i) Decentralised: The network is decentralised. A group of nodes maintains the network making it decentralised. As the system doesn’t require any governing authority, the users can directly access it from the web and store  assets there.

ii) Immutability: Immutability is something that can’t be changed or altered. It ensures that the technology will remain as it is a permanent, unalterable network. As it is a distributed system, every node on the system has a copy of the digital ledger. When a transaction is added every node needs to check its validity. If the majority thinks it’s valid, then it’s added to the ledger. This promotes transparency and makes it corruption-proof. Without the majority consent from the nodes, no one can add any transaction blocks to the ledger. Once the transaction blocks are added to the ledger, no one can change it. Thus, any user on the network won’t be able to edit, delete or update it.

iii) Enhanced security: As it gets rid of the need for a central authority, no one can just simply change any characteristics of the network for their benefit. Using encryption ensures another layer of security for the system. Every information on the blockchain is hashed cryptographically. So, changing or trying to tamper with the data means changing all the hash IDs. If someone wants to corrupt the network, he/she would have to alter every data stored on every node in the network. There could be millions and millions of people, where everyone has the same copy of the ledger.

iv) Distributed ledger: A public ledger will provide every information about a transaction and the participant nodes. Many people can see what really goes on in the ledger. The ledger on the network is maintained by all other users on the system. Distributed ledger responds really well to any suspicious activity or tamper. Nodes act as verifiers of the ledger. If a user wants to add a new block others would have to verify the transaction and then give the green signal. To make the blockchain features work, every active node has to maintain the ledger and participate for validation.

v) Consensus: Every blockchain succeeds because of the consensus algorithms. Every blockchain has a consensus to help the network make any transactions. In simple terms, the consensus is a decision-making process for the group of nodes active on the network. Here, the nodes can come to an agreement quickly and relatively faster. When millions of nodes are validating a transaction, a consensus is absolutely necessary for a system to run smoothly. Nodes might not trust each other, but they can trust the algorithms that run at the core of it.

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