Which of the following statements regarding the features of blockchain technology are correct? 1. Records stored in the database may be made visible to relevant stakeholders without risk of alteration. 2. Copies of the entire database are stored on multiple computers on a network, syncing within seconds. 3. Consortium blockchain is a blend of public and private blockchains allowing selective data access. 4. Mathematical algorithms make it impossible to change or delete any data once recorded and accepted. Select the answer using the code given below :

Correct Answer: Option C

Blockchain technology is a distributed ledger system characterized by decentralization, immutability, and transparency. These core features are widely recognized in standard government frameworks, such as NITI Aayog's 2020 discussion paper, 'Blockchain: The India Strategy.'

• Statement 1 is correct: Blockchain provides "adjustable transparency." Through cryptography and smart contracts, records stored in the database can be made visible to relevant stakeholders without any risk of unauthorized alteration.
• Statement 2 is correct: Blockchain operates as a distributed ledger. Copies of the entire database are stored across multiple autonomous computers (nodes) on a peer-to-peer network. These nodes communicate and sync new data blocks within seconds, ensuring no single point of failure.
• Statement 4 is correct: Immutability is a foundational feature. Mathematical algorithms (such as cryptographic hash functions) link each block to the previous one. Once data is recorded and accepted by the network's consensus, it is impossible to change or delete it without altering all subsequent blocks.
• Statement 3 is incorrect: The statement actually defines a hybrid blockchain, which blends the architectural features of both public and private blockchains to allow selective data access. In contrast, a consortium blockchain (or federated blockchain) is a semi-decentralized network governed collectively by a predefined group of multiple organizations (e.g., a consortium of banks), rather than being a structural blend of public and private networks.

Takeaway: To distinguish blockchain architectures, remember: Public = Anyone can join; Private = Governed by one entity; Consortium = Governed by a group of entities; Hybrid = A structural mix of public and private features.