UPSC CSE Prelims
Question 54
Which of the following statements regarding the features of blockchain technology are correct?
- Records stored in the database may be made visible to relevant stakeholders without risk of alteration.
- Copies of the entire database are stored on multiple computers on a network, syncing within seconds.
- Consortium blockchain is a blend of public and private blockchains allowing selective data access.
- Mathematical algorithms make it impossible to change or delete any data once recorded and accepted.
Select the answer using the code given below:
View correct answer and explanation
Correct answer: C
Correct Option: C
Explanation: Blockchains replicate validated transaction records, use cryptographic consensus and can be permissioned; however, absolute immutability and instant replication are oversimplifications.
Statement-wise Analysis:
Statement 1: Correct - Shared ledgers may allow authorised parties to verify records and detect unauthorised alteration.
Statement 2: Correct - Blockchain nodes keep replicated ledger copies, although synchronisation times vary by network.
Statement 3: Incorrect - A consortium blockchain is permissioned among selected organisations; calling it simply a blend of public and private networks is imprecise.
Statement 4: Correct - Accepted records are intended to be computationally tamper-resistant through cryptography and consensus.
Option-wise Analysis:
A: Incorrect - Includes unsupported item(s) 3 and omits supported item(s) 2, 4.
B: Incorrect - Omits supported item(s) 1.
C: Correct - This option includes the supported item(s) and excludes the unsupported ones.
D: Incorrect - Omits supported item(s) 2.
Review note: Source overstatement: mathematical algorithms do not make alterations literally impossible; consensus reorganisation, governance changes and attacks can change a blockchain. Key includes item 4 only under conventional simplification.