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:
Correct answer: C
Explanation
Blockchain ledgers are append-only and visible to permissioned stakeholders without alteration risk (1 correct). The distributed ledger is replicated across nodes that sync in seconds (2 correct). Cryptographic hashing plus consensus make recorded blocks effectively immutable (4 correct). Statement 3 describes a consortium chain as a 'blend of public and private blockchains' — strictly, a consortium chain is a type of permissioned blockchain governed by a group of organisations, not a hybrid public-private chain (that is a 'hybrid blockchain'). Hence 1, 2 and 4 are correct. (Early consensus; verify with official UPSC key.)