By signing in you confirm you are 18 or older, or have your parent’s or guardian’s consent.

UPSC Prelims 2026 GS Paper 1, question 86

Topic: Science and technology

Q86

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 :

  1. (a) 1 and 3
  2. (b) 2 and 4 only
  3. (c) 1, 2 and 4Correct answer
  4. (d) 1 and 4 only

Solution.

Answer: (c) 1, 2 and 4

  1. Statements 1 and 2 are correct: a blockchain is a distributed ledger where copies of the database are synchronized across network nodes within seconds and records are visible to authorized participants without risk of unilateral alteration.
  2. Statement 3 is incorrect: a blend of public and private blockchains allowing selective public/private data access is defined as a 'hybrid blockchain', whereas a 'consortium (federated) blockchain' is a permissioned network governed jointly by a group of pre-selected organizations.
  3. Statement 4 is correct: cryptographic hashing and consensus algorithms make accepted blocks practically immutable, preventing retroactive modification or deletion of recorded data.